20399031 has 12 divisors (see below), whose sum is σ = 31198752. Its totient is φ = 12799296.

The previous prime is 20399009. The next prime is 20399033. The reversal of 20399031 is 13099302.

It is not a de Polignac number, because 20399031 - 2⁶ = 20398967 is a prime.

It is a super-2 number, since 2×20399031² = 832240931477922, which contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 20398986 and 20399004.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20399033) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 66511 + ... + 66816.

It is an arithmetic number, because the mean of its divisors is an integer number (2599896).

Almost surely, 2^20399031 is an apocalyptic number.

20399031 is a deficient number, since it is larger than the sum of its proper divisors (10799721).

20399031 is a wasteful number, since it uses less digits than its factorization.

20399031 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 133350 (or 133347 counting only the distinct ones).

The product of its (nonzero) digits is 1458, while the sum is 27.

The square root of 20399031 is about 4516.5286448776. The cubic root of 20399031 is about 273.2351152498.

The spelling of 20399031 in words is "twenty million, three hundred ninety-nine thousand, thirty-one".