27821916869985 has 80 divisors (see below), whose sum is σ = 56999373881472. Its totient is φ = 12718312588800.

The previous prime is 27821916869963. The next prime is 27821916870023. The reversal of 27821916869985 is 58996861912872.

27821916869985 is a `hidden beast` number, since 278 + 2 + 191 + 6 + 86 + 9 + 9 + 85 = 666.

It is not a de Polignac number, because 27821916869985 - 2⁵ = 27821916869953 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (81).

It is an unprimeable number.

It is a polite number, since it can be written in 79 ways as a sum of consecutive naturals, for example, 187492270 + ... + 187640600.

Almost surely, 2^{27821916869985} is an apocalyptic number.

It is an amenable number.

27821916869985 is an abundant number, since it is smaller than the sum of its proper divisors (29177457011487).

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

27821916869985 is a wasteful number, since it uses less digits than its factorization.

27821916869985 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 214516 (or 214507 counting only the distinct ones).

The product of its digits is 1881169920, while the sum is 81.

The spelling of 27821916869985 in words is "twenty-seven trillion, eight hundred twenty-one billion, nine hundred sixteen million, eight hundred sixty-nine thousand, nine hundred eighty-five".