20051531031 has 24 divisors (see below), whose sum is σ = 32452527744. Its totient is φ = 10959841200.

The previous prime is 20051531029. The next prime is 20051531033. The reversal of 20051531031 is 13013515002.

It is an interprime number because it is at equal distance from previous prime (20051531029) and next prime (20051531033).

It is not a de Polignac number, because 20051531031 - 2¹ = 20051531029 is a prime.

It is a super-2 number, since 2×20051531031² (a number of 21 digits) contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (21).

It is a junction number, because it is equal to n+sod(n) for n = 20051530989 and 20051531007.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20051531033) 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, 2961945 + ... + 2968706.

It is an arithmetic number, because the mean of its divisors is an integer number (1352188656).

Almost surely, 2^20051531031 is an apocalyptic number.

20051531031 is a gapful number since it is divisible by the number (21) formed by its first and last digit.

20051531031 is a deficient number, since it is larger than the sum of its proper divisors (12400996713).

20051531031 is a wasteful number, since it uses less digits than its factorization.

20051531031 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5930691 (or 5930684 counting only the distinct ones).

The product of its (nonzero) digits is 450, while the sum is 21.

The spelling of 20051531031 in words is "twenty billion, fifty-one million, five hundred thirty-one thousand, thirty-one".