20531031020 has 96 divisors (see below), whose sum is σ = 45918835200. Its totient is φ = 7688991744.

The previous prime is 20531031011. The next prime is 20531031049. The reversal of 20531031020 is 2013013502.

It is a self number, because there is not a number n which added to its sum of digits gives 20531031020.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 27781811 + ... + 27782549.

It is an arithmetic number, because the mean of its divisors is an integer number (478321200).

Almost surely, 2^20531031020 is an apocalyptic number.

20531031020 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 20531031020, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (22959417600).

20531031020 is an abundant number, since it is smaller than the sum of its proper divisors (25387804180).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

20531031020 is a wasteful number, since it uses less digits than its factorization.

20531031020 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1527 (or 1525 counting only the distinct ones).

The product of its (nonzero) digits is 180, while the sum is 17.

Adding to 20531031020 its reverse (2013013502), we get a palindrome (22544044522).

The spelling of 20531031020 in words is "twenty billion, five hundred thirty-one million, thirty-one thousand, twenty".