20732531 has 4 divisors (see below), whose sum is σ = 20785152. Its totient is φ = 20679912.

The previous prime is 20732513. The next prime is 20732567. The reversal of 20732531 is 13523702.

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

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-20732531 is a prime.

It is a super-2 number, since 2×20732531² = 859675683331922, which contains 22 as substring.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 20732497 and 20732506.

It is not an unprimeable number, because it can be changed into a prime (20732501) 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, 25715 + ... + 26508.

It is an arithmetic number, because the mean of its divisors is an integer number (5196288).

Almost surely, 2^20732531 is an apocalyptic number.

20732531 is a deficient number, since it is larger than the sum of its proper divisors (52621).

20732531 is an equidigital number, since it uses as much as digits as its factorization.

20732531 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 52620.

The product of its (nonzero) digits is 1260, while the sum is 23.

The square root of 20732531 is about 4553.2989139744. The cubic root of 20732531 is about 274.7160970895.

The spelling of 20732531 in words is "twenty million, seven hundred thirty-two thousand, five hundred thirty-one".