20500531 has 2 divisors, whose sum is σ = 20500532. Its totient is φ = 20500530.

The previous prime is 20500523. The next prime is 20500541. The reversal of 20500531 is 13500502.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 20500531 - 2³ = 20500523 is a prime.

It is a super-2 number, since 2×20500531² = 840543542563922, which contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (20500511) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10250265 + 10250266.

It is an arithmetic number, because the mean of its divisors is an integer number (10250266).

Almost surely, 2^20500531 is an apocalyptic number.

20500531 is a deficient number, since it is larger than the sum of its proper divisors (1).

20500531 is an equidigital number, since it uses as much as digits as its factorization.

20500531 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 150, while the sum is 16.

The square root of 20500531 is about 4527.7512078293. The cubic root of 20500531 is about 273.6875467574.

The spelling of 20500531 in words is "twenty million, five hundred thousand, five hundred thirty-one".