161455501521 has 12 divisors (see below), whose sum is σ = 233246427648. Its totient is φ = 107621804664.

The previous prime is 161455501513. The next prime is 161455501549. The reversal of 161455501521 is 125105554161.

161455501521 is a `hidden beast` number, since 1 + 6 + 1 + 455 + 50 + 152 + 1 = 666.

It is not a de Polignac number, because 161455501521 - 2³ = 161455501513 is a prime.

It is not an unprimeable number, because it can be changed into a prime (161455502521) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 1198885 + ... + 1326738.

It is an arithmetic number, because the mean of its divisors is an integer number (19437202304).

Almost surely, 2^161455501521 is an apocalyptic number.

It is an amenable number.

161455501521 is a deficient number, since it is larger than the sum of its proper divisors (71790926127).

161455501521 is a wasteful number, since it uses less digits than its factorization.

161455501521 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2532732 (or 2532729 counting only the distinct ones).

The product of its (nonzero) digits is 30000, while the sum is 36.

It can be divided in two parts, 161455 and 501521, that added together give a triangular number (662976 = T₁₁₅₁).

The spelling of 161455501521 in words is "one hundred sixty-one billion, four hundred fifty-five million, five hundred one thousand, five hundred twenty-one".