20831431 has 8 divisors (see below), whose sum is σ = 21177920. Its totient is φ = 20487168.

The previous prime is 20831323. The next prime is 20831533. The reversal of 20831431 is 13413802.

20831431 = 474² + 475² + ... + 552².

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

It is a cyclic number.

It is not a de Polignac number, because 20831431 - 2¹³ = 20823239 is a prime.

It is a super-2 number, since 2×20831431² = 867897035015522, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20831131) 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, 35815 + ... + 36391.

It is an arithmetic number, because the mean of its divisors is an integer number (2647240).

Almost surely, 2^20831431 is an apocalyptic number.

20831431 is a deficient number, since it is larger than the sum of its proper divisors (346489).

20831431 is an equidigital number, since it uses as much as digits as its factorization.

20831431 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1113.

The product of its (nonzero) digits is 576, while the sum is 22.

The square root of 20831431 is about 4564.1462509433. The cubic root of 20831431 is about 275.1522286646.

The spelling of 20831431 in words is "twenty million, eight hundred thirty-one thousand, four hundred thirty-one".