51564404069 has 2 divisors, whose sum is σ = 51564404070. Its totient is φ = 51564404068.

The previous prime is 51564404009. The next prime is 51564404077. The reversal of 51564404069 is 96040446515.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 30644253025 + 20920151044 = 175055^2 + 144638^2 .

It is a cyclic number.

It is not a de Polignac number, because 51564404069 - 2¹⁶ = 51564338533 is a prime.

It is a super-2 number, since 2×51564404069² (a number of 22 digits) contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (51564404009) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 25782202034 + 25782202035.

It is an arithmetic number, because the mean of its divisors is an integer number (25782202035).

Almost surely, 2^51564404069 is an apocalyptic number.

It is an amenable number.

51564404069 is a deficient number, since it is larger than the sum of its proper divisors (1).

51564404069 is an equidigital number, since it uses as much as digits as its factorization.

51564404069 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 518400, while the sum is 44.

The spelling of 51564404069 in words is "fifty-one billion, five hundred sixty-four million, four hundred four thousand, sixty-nine".