20400539 has 2 divisors, whose sum is σ = 20400540. Its totient is φ = 20400538.

The previous prime is 20400521. The next prime is 20400577. The reversal of 20400539 is 93500402.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 20400539 - 2²⁰ = 19351963 is a prime.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (20400599) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10200269 + 10200270.

It is an arithmetic number, because the mean of its divisors is an integer number (10200270).

Almost surely, 2^20400539 is an apocalyptic number.

20400539 is a deficient number, since it is larger than the sum of its proper divisors (1).

20400539 is an equidigital number, since it uses as much as digits as its factorization.

20400539 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 1080, while the sum is 23.

The square root of 20400539 is about 4516.6955841633. The cubic root of 20400539 is about 273.2418480598.

The spelling of 20400539 in words is "twenty million, four hundred thousand, five hundred thirty-nine".