20565331 has 2 divisors, whose sum is σ = 20565332. Its totient is φ = 20565330.

The previous prime is 20565323. The next prime is 20565371. The reversal of 20565331 is 13356502.

It is a happy number.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 20565331 - 2³ = 20565323 is a prime.

It is a super-2 number, since 2×20565331² = 845865678279122, which contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 20565296 and 20565305.

It is not a weakly prime, because it can be changed into another prime (20565301) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10282665 + 10282666.

It is an arithmetic number, because the mean of its divisors is an integer number (10282666).

Almost surely, 2^20565331 is an apocalyptic number.

20565331 is a deficient number, since it is larger than the sum of its proper divisors (1).

20565331 is an equidigital number, since it uses as much as digits as its factorization.

20565331 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 2700, while the sum is 25.

The square root of 20565331 is about 4534.9014322254. The cubic root of 20565331 is about 273.9756092093.

It can be divided in two parts, 205 and 65331, that added together give a 16-th power (65536 = 2¹⁶).

The spelling of 20565331 in words is "twenty million, five hundred sixty-five thousand, three hundred thirty-one".