161010390121 has 45 divisors (see below), whose sum is σ = 198701631933. Its totient is φ = 130441925880.

The previous prime is 161010390109. The next prime is 161010390137. The reversal of 161010390121 is 121093010161.

The square root of 161010390121 is 401261.

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

It is a de Polignac number, because none of the positive numbers 2^k-161010390121 is a prime.

It is a super-2 number, since 2×161010390121² (a number of 23 digits) contains 22 as substring.

It is a hoax number, since the sum of its digits (25) coincides with the sum of the digits of its distinct prime factors.

It is not an unprimeable number, because it can be changed into a prime (161010390421) by changing a digit.

It is a polite number, since it can be written in 44 ways as a sum of consecutive naturals, for example, 373573776 + ... + 373574206.

Almost surely, 2^161010390121 is an apocalyptic number.

161010390121 is the 401261-st square number.

161010390121 is the 200631-st centered octagonal number.

It is an amenable number.

161010390121 is a deficient number, since it is larger than the sum of its proper divisors (37691241812).

161010390121 is an frugal number, since it uses more digits than its factorization.

161010390121 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 928 (or 457 counting only the distinct ones).

The product of its (nonzero) digits is 324, while the sum is 25.

Multiplying 161010390121 by its sum of digits (25), we get a square (4025259753025 = 2006305²).

Multiplying 161010390121 by its product of nonzero digits (324), we get a square (52167366399204 = 7222698²).

The spelling of 161010390121 in words is "one hundred sixty-one billion, ten million, three hundred ninety thousand, one hundred twenty-one".