20465531 has 2 divisors, whose sum is σ = 20465532. Its totient is φ = 20465530.

The previous prime is 20465521. The next prime is 20465563. The reversal of 20465531 is 13556402.

It is a weak prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-20465531 is a prime.

It is a super-2 number, since 2×20465531² = 837675918223922, which contains 22 as substring.

It is a Sophie Germain prime.

It is a Chen prime.

It is a self number, because there is not a number n which added to its sum of digits gives 20465531.

It is not a weakly prime, because it can be changed into another prime (20465521) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10232765 + 10232766.

It is an arithmetic number, because the mean of its divisors is an integer number (10232766).

Almost surely, 2^20465531 is an apocalyptic number.

20465531 is a deficient number, since it is larger than the sum of its proper divisors (1).

20465531 is an equidigital number, since it uses as much as digits as its factorization.

20465531 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 3600, while the sum is 26.

The square root of 20465531 is about 4523.8845033887. The cubic root of 20465531 is about 273.5317049296.

The spelling of 20465531 in words is "twenty million, four hundred sixty-five thousand, five hundred thirty-one".