27921977015625 has 945 divisors, whose sum is σ = 67775493458673. Its totient is φ = 11413710000000.

The previous prime is 27921977015579. The next prime is 27921977015717. The reversal of 27921977015625 is 52651077912972.

It is a happy number.

The square root of 27921977015625 is 5284125.

It is a perfect power (a square), and thus also a powerful number.

27921977015625 is a `hidden beast` number, since 279 + 2 + 197 + 7 + 0 + 156 + 25 = 666.

It can be written as a sum of positive squares in 10 ways, for example, as 7406077830921 + 20515899184704 = 2721411^2 + 4529448^2 .

It is a tau number, because it is divible by the number of its divisors (945).

It is not a de Polignac number, because 27921977015625 - 2¹¹ = 27921977013577 is a prime.

It is a super-2 number, since 2×27921977015625² (a number of 28 digits) contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (63).

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 944 ways as a sum of consecutive naturals, for example, 457737328095 + ... + 457737328155.

Almost surely, 2^{27921977015625} is an apocalyptic number.

27921977015625 is a gapful number since it is divisible by the number (25) formed by its first and last digit.

27921977015625 is the 5284125-th square number.

27921977015625 is the 2642063-rd centered octagonal number.

It is an amenable number.

27921977015625 is an abundant number, since it is smaller than the sum of its proper divisors (39853516443048).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

27921977015625 is an frugal number, since it uses more digits than its factorization.

27921977015625 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 200 (or 87 counting only the distinct ones).

The product of its (nonzero) digits is 33339600, while the sum is 63.

The spelling of 27921977015625 in words is "twenty-seven trillion, nine hundred twenty-one billion, nine hundred seventy-seven million, fifteen thousand, six hundred twenty-five".