20521988031 has 4 divisors (see below), whose sum is σ = 27362650712. Its totient is φ = 13681325352.

The previous prime is 20521988017. The next prime is 20521988033. The reversal of 20521988031 is 13088912502.

It is a semiprime because it is the product of two primes.

It is not a de Polignac number, because 20521988031 - 2⁵ = 20521987999 is a prime.

It is a super-2 number, since 2×20521988031² (a number of 21 digits) 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 (20521988033) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 3420331336 + ... + 3420331341.

It is an arithmetic number, because the mean of its divisors is an integer number (6840662678).

Almost surely, 2^20521988031 is an apocalyptic number.

20521988031 is a deficient number, since it is larger than the sum of its proper divisors (6840662681).

20521988031 is an equidigital number, since it uses as much as digits as its factorization.

20521988031 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6840662680.

The product of its (nonzero) digits is 34560, while the sum is 39.

The spelling of 20521988031 in words is "twenty billion, five hundred twenty-one million, nine hundred eighty-eight thousand, thirty-one".