123621931 has 4 divisors (see below), whose sum is σ = 123644232. Its totient is φ = 123599632.

The previous prime is 123621919. The next prime is 123621959. The reversal of 123621931 is 139126321.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length.

It is a cyclic number.

It is not a de Polignac number, because 123621931 - 2⁵ = 123621899 is a prime.

It is a super-2 number, since 2×123621931² = 30564763648337522, which contains 22 as substring.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 123621931.

It is not an unprimeable number, because it can be changed into a prime (123621991) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 4320 + ... + 16306.

It is an arithmetic number, because the mean of its divisors is an integer number (30911058).

Almost surely, 2^123621931 is an apocalyptic number.

123621931 is a deficient number, since it is larger than the sum of its proper divisors (22301).

123621931 is a wasteful number, since it uses less digits than its factorization.

123621931 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 22300.

The product of its digits is 1944, while the sum is 28.

The square root of 123621931 is about 11118.5399671000. The cubic root of 123621931 is about 498.1557807406.

The spelling of 123621931 in words is "one hundred twenty-three million, six hundred twenty-one thousand, nine hundred thirty-one".