20875531 has 2 divisors, whose sum is σ = 20875532. Its totient is φ = 20875530.

The previous prime is 20875523. The next prime is 20875549. The reversal of 20875531 is 13557802.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 20875531 - 2³ = 20875523 is a prime.

It is a super-2 number, since 2×20875531² = 871575589063922, which contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 20875493 and 20875502.

It is not a weakly prime, because it can be changed into another prime (20875831) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10437765 + 10437766.

It is an arithmetic number, because the mean of its divisors is an integer number (10437766).

Almost surely, 2^20875531 is an apocalyptic number.

20875531 is a deficient number, since it is larger than the sum of its proper divisors (1).

20875531 is an equidigital number, since it uses as much as digits as its factorization.

20875531 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 8400, while the sum is 31.

The square root of 20875531 is about 4568.9748303093. The cubic root of 20875531 is about 275.3462569522.

The spelling of 20875531 in words is "twenty million, eight hundred seventy-five thousand, five hundred thirty-one".