19776680621604 has 135 divisors (see below), whose sum is σ = 54924007436067. Its totient is φ = 6204021901056.

The previous prime is 19776680621549. The next prime is 19776680621609. The reversal of 19776680621604 is 40612608667791.

It is a happy number.

The square root of 19776680621604 is 4447098.

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

19776680621604 is a `hidden beast` number, since 19 + 7 + 7 + 6 + 6 + 8 + 0 + 6 + 2 + 1 + 604 = 666.

It can be written as a sum of positive squares in 4 ways, for example, as 2574426668004 + 17202253953600 = 1604502^2 + 4147560^2 .

It is a super-2 number, since 2×19776680621604² (a number of 27 digits) contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (19776680621609) by changing a digit.

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 44 ways as a sum of consecutive naturals, for example, 1360804722 + ... + 1360819254.

Almost surely, 2^{19776680621604} is an apocalyptic number.

19776680621604 is the 4447098-th square number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 19776680621604

19776680621604 is an abundant number, since it is smaller than the sum of its proper divisors (35147326814463).

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

19776680621604 is an frugal number, since it uses more digits than its factorization.

19776680621604 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 29116 (or 14555 counting only the distinct ones).

The product of its (nonzero) digits is 36578304, while the sum is 63.

The spelling of 19776680621604 in words is "nineteen trillion, seven hundred seventy-six billion, six hundred eighty million, six hundred twenty-one thousand, six hundred four".