161851726864 has 45 divisors (see below), whose sum is σ = 321187375263. Its totient is φ = 79010072736.

The previous prime is 161851726843. The next prime is 161851726901. The reversal of 161851726864 is 468627158161.

The square root of 161851726864 is 402308.

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

It is a Duffinian number.

It is an unprimeable number.

It is a polite number, since it can be written in 8 ways as a sum of consecutive naturals, for example, 69195807 + ... + 69198145.

Almost surely, 2^161851726864 is an apocalyptic number.

161851726864 is the 402308-th square number.

It is an amenable number.

161851726864 is a deficient number, since it is larger than the sum of its proper divisors (159335648399).

161851726864 is an frugal number, since it uses more digits than its factorization.

161851726864 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4772 (or 2384 counting only the distinct ones).

The product of its digits is 3870720, while the sum is 55.

The spelling of 161851726864 in words is "one hundred sixty-one billion, eight hundred fifty-one million, seven hundred twenty-six thousand, eight hundred sixty-four".