161231072 has 48 divisors (see below), whose sum is σ = 324011520. Its totient is φ = 78962688.

The previous prime is 161231051. The next prime is 161231087. The reversal of 161231072 is 270132161.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 394004 + ... + 394412.

It is an arithmetic number, because the mean of its divisors is an integer number (6750240).

Almost surely, 2^161231072 is an apocalyptic number.

It is an amenable number.

161231072 is an abundant number, since it is smaller than the sum of its proper divisors (162780448).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

161231072 is a wasteful number, since it uses less digits than its factorization.

161231072 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 643 (or 635 counting only the distinct ones).

The product of its (nonzero) digits is 504, while the sum is 23.

The square root of 161231072 is about 12697.6797880558. The cubic root of 161231072 is about 544.2723189638.

The spelling of 161231072 in words is "one hundred sixty-one million, two hundred thirty-one thousand, seventy-two".