623991121 has 12 divisors (see below), whose sum is σ = 677401396. Its totient is φ = 571390560.

The previous prime is 623991107. The next prime is 623991163. The reversal of 623991121 is 121199326.

It can be written as a sum of positive squares in 2 ways, for example, as 268140625 + 355850496 = 16375^2 + 18864^2 .

It is not a de Polignac number, because 623991121 - 2¹¹ = 623989073 is a prime.

It is a hoax number, since the sum of its digits (34) coincides with the sum of the digits of its distinct prime factors.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (623991721) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 221695 + ... + 224491.

Almost surely, 2^623991121 is an apocalyptic number.

It is an amenable number.

623991121 is a deficient number, since it is larger than the sum of its proper divisors (53410275).

623991121 is a wasteful number, since it uses less digits than its factorization.

623991121 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3072 (or 2941 counting only the distinct ones).

The product of its digits is 5832, while the sum is 34.

The square root of 623991121 is about 24979.8142707267. The cubic root of 623991121 is about 854.5276832289.

The spelling of 623991121 in words is "six hundred twenty-three million, nine hundred ninety-one thousand, one hundred twenty-one".