156055811521 has 3 divisors (see below), whose sum is σ = 156056206561. Its totient is φ = 156055416482.

The previous prime is 156055811449. The next prime is 156055811531. The reversal of 156055811521 is 125118550651.

It is a happy number.

The square root of 156055811521 is 395039.

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

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length, and also an emirpimes, since its reverse is a distinct semiprime: 125118550651 = 81931 ⋅1527121.

It is not a de Polignac number, because 156055811521 - 2¹¹ = 156055809473 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (156055811531) by changing a digit.

It is a polite number, since it can be written in 2 ways as a sum of consecutive naturals, for example, 197520 + ... + 592558.

Almost surely, 2^156055811521 is an apocalyptic number.

156055811521 is the 395039-th square number.

156055811521 is the 197520-th centered octagonal number.

It is an amenable number.

156055811521 is a deficient number, since it is larger than the sum of its proper divisors (395040).

156055811521 is an frugal number, since it uses more digits than its factorization.

156055811521 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 790078 (or 395039 counting only the distinct ones).

The product of its (nonzero) digits is 60000, while the sum is 40.

The spelling of 156055811521 in words is "one hundred fifty-six billion, fifty-five million, eight hundred eleven thousand, five hundred twenty-one".