161491672 has 16 divisors (see below), whose sum is σ = 304612560. Its totient is φ = 80261664.

The previous prime is 161491669. The next prime is 161491699. The reversal of 161491672 is 276194161.

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 3 ways as a sum of consecutive naturals, for example, 59103 + ... + 61774.

It is an arithmetic number, because the mean of its divisors is an integer number (19038285).

Almost surely, 2^161491672 is an apocalyptic number.

It is an amenable number.

161491672 is a deficient number, since it is larger than the sum of its proper divisors (143120888).

161491672 is a wasteful number, since it uses less digits than its factorization.

161491672 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 121050 (or 121046 counting only the distinct ones).

The product of its digits is 18144, while the sum is 37.

The square root of 161491672 is about 12707.9373621371. The cubic root of 161491672 is about 544.5653993963.

The spelling of 161491672 in words is "one hundred sixty-one million, four hundred ninety-one thousand, six hundred seventy-two".