161731923 has 8 divisors (see below), whose sum is σ = 219177936. Its totient is φ = 106053600.

The previous prime is 161731909. The next prime is 161731943. The reversal of 161731923 is 329137161.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 161731923 - 2⁶ = 161731859 is a prime.

It is not an unprimeable number, because it can be changed into a prime (161731943) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 441708 + ... + 442073.

It is an arithmetic number, because the mean of its divisors is an integer number (27397242).

Almost surely, 2^161731923 is an apocalyptic number.

161731923 is a deficient number, since it is larger than the sum of its proper divisors (57446013).

161731923 is an equidigital number, since it uses as much as digits as its factorization.

161731923 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 883845.

The product of its digits is 6804, while the sum is 33.

The square root of 161731923 is about 12717.3866419166. The cubic root of 161731923 is about 544.8353153905.

The spelling of 161731923 in words is "one hundred sixty-one million, seven hundred thirty-one thousand, nine hundred twenty-three".