161290440265 has 32 divisors (see below), whose sum is σ = 199116403200. Its totient is φ = 125362308864.

The previous prime is 161290440263. The next prime is 161290440281. The reversal of 161290440265 is 562044092161.

It is a cyclic number.

It is not a de Polignac number, because 161290440265 - 2¹ = 161290440263 is a prime.

It is a super-2 number, since 2×161290440265² (a number of 23 digits) contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (161290440263) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 71907234 + ... + 71909476.

It is an arithmetic number, because the mean of its divisors is an integer number (6222387600).

Almost surely, 2^161290440265 is an apocalyptic number.

It is an amenable number.

161290440265 is a deficient number, since it is larger than the sum of its proper divisors (37825962935).

161290440265 is a wasteful number, since it uses less digits than its factorization.

161290440265 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4401.

The product of its (nonzero) digits is 103680, while the sum is 40.

The spelling of 161290440265 in words is "one hundred sixty-one billion, two hundred ninety million, four hundred forty thousand, two hundred sixty-five".