156688513921 has 15 divisors (see below), whose sum is σ = 163351619013. Its totient is φ = 150292151520.

The previous prime is 156688513903. The next prime is 156688513963. The reversal of 156688513921 is 129315886651.

The square root of 156688513921 is 395839.

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

It can be written as a sum of positive squares in 2 ways, for example, as 145839208321 + 10849305600 = 381889^2 + 104160^2 .

It is not a de Polignac number, because 156688513921 - 2⁵ = 156688513889 is a prime.

It is a Duffinian number.

Its product of digits (3110400) is a multiple of the sum of its prime divisors (144).

It is not an unprimeable number, because it can be changed into a prime (156688513981) by changing a digit.

It is a polite number, since it can be written in 14 ways as a sum of consecutive naturals, for example, 1386623961 + ... + 1386624073.

Almost surely, 2^156688513921 is an apocalyptic number.

156688513921 is the 395839-th square number.

156688513921 is the 197920-th centered octagonal number.

It is an amenable number.

156688513921 is a deficient number, since it is larger than the sum of its proper divisors (6663105092).

156688513921 is an frugal number, since it uses more digits than its factorization.

156688513921 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 514 (or 144 counting only the distinct ones).

The product of its digits is 3110400, while the sum is 55.

The spelling of 156688513921 in words is "one hundred fifty-six billion, six hundred eighty-eight million, five hundred thirteen thousand, nine hundred twenty-one".