20881431 has 24 divisors (see below), whose sum is σ = 31438160. Its totient is φ = 13343616.

The previous prime is 20881381. The next prime is 20881433. The reversal of 20881431 is 13418802.

It is not a de Polignac number, because 20881431 - 2⁷ = 20881303 is a prime.

It is a super-2 number, since 2×20881431² = 872068321215522, which contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 20881395 and 20881404.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20881433) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 23880 + ... + 24738.

Almost surely, 2^20881431 is an apocalyptic number.

20881431 is a deficient number, since it is larger than the sum of its proper divisors (10556729).

20881431 is a wasteful number, since it uses less digits than its factorization.

20881431 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 975 (or 972 counting only the distinct ones).

The product of its (nonzero) digits is 1536, while the sum is 27.

The square root of 20881431 is about 4569.6204437568. The cubic root of 20881431 is about 275.3721946540.

It can be divided in two parts, 20881 and 431, that added together give a palindrome (21312).

The spelling of 20881431 in words is "twenty million, eight hundred eighty-one thousand, four hundred thirty-one".