20565667 has 2 divisors, whose sum is σ = 20565668. Its totient is φ = 20565666.

The previous prime is 20565659. The next prime is 20565691. The reversal of 20565667 is 76656502.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 20565667 - 2³ = 20565659 is a prime.

It is not a weakly prime, because it can be changed into another prime (20565607) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10282833 + 10282834.

It is an arithmetic number, because the mean of its divisors is an integer number (10282834).

Almost surely, 2^20565667 is an apocalyptic number.

20565667 is a deficient number, since it is larger than the sum of its proper divisors (1).

20565667 is an equidigital number, since it uses as much as digits as its factorization.

20565667 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 75600, while the sum is 37.

The square root of 20565667 is about 4534.9384780832. The cubic root of 20565667 is about 273.9771012885.

The spelling of 20565667 in words is "twenty million, five hundred sixty-five thousand, six hundred sixty-seven".