51720118399 has 2 divisors, whose sum is σ = 51720118400. Its totient is φ = 51720118398.

The previous prime is 51720118363. The next prime is 51720118447. The reversal of 51720118399 is 99381102715.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 51720118399 - 2⁷ = 51720118271 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (51720118309) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 25860059199 + 25860059200.

It is an arithmetic number, because the mean of its divisors is an integer number (25860059200).

Almost surely, 2^51720118399 is an apocalyptic number.

51720118399 is a deficient number, since it is larger than the sum of its proper divisors (1).

51720118399 is an equidigital number, since it uses as much as digits as its factorization.

51720118399 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 136080, while the sum is 46.

The spelling of 51720118399 in words is "fifty-one billion, seven hundred twenty million, one hundred eighteen thousand, three hundred ninety-nine".