161720572 has 12 divisors (see below), whose sum is σ = 304781176. Its totient is φ = 74640240.

The previous prime is 161720509. The next prime is 161720621. The reversal of 161720572 is 275027161.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1554954 + ... + 1555057.

Almost surely, 2^161720572 is an apocalyptic number.

It is an amenable number.

161720572 is a deficient number, since it is larger than the sum of its proper divisors (143060604).

161720572 is a wasteful number, since it uses less digits than its factorization.

161720572 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3110028 (or 3110026 counting only the distinct ones).

The product of its (nonzero) digits is 5880, while the sum is 31.

The square root of 161720572 is about 12716.9403552899. The cubic root of 161720572 is about 544.8225688442.

The spelling of 161720572 in words is "one hundred sixty-one million, seven hundred twenty thousand, five hundred seventy-two".