51564404009 has 2 divisors, whose sum is σ = 51564404010. Its totient is φ = 51564404008.

The previous prime is 51564403987. The next prime is 51564404069. The reversal of 51564404009 is 90040446515.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 29542734400 + 22021669609 = 171880^2 + 148397^2 .

It is a cyclic number.

It is not a de Polignac number, because 51564404009 - 2²⁰ = 51563355433 is a prime.

It is not a weakly prime, because it can be changed into another prime (51564404069) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 25782202004 + 25782202005.

It is an arithmetic number, because the mean of its divisors is an integer number (25782202005).

Almost surely, 2^51564404009 is an apocalyptic number.

It is an amenable number.

51564404009 is a deficient number, since it is larger than the sum of its proper divisors (1).

51564404009 is an equidigital number, since it uses as much as digits as its factorization.

51564404009 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 86400, while the sum is 38.

The spelling of 51564404009 in words is "fifty-one billion, five hundred sixty-four million, four hundred four thousand, nine".