51381988687 has 2 divisors, whose sum is σ = 51381988688. Its totient is φ = 51381988686.

The previous prime is 51381988673. The next prime is 51381988699. The reversal of 51381988687 is 78688918315.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-51381988687 is a prime.

It is a super-2 number, since 2×51381988687² (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 (51381988627) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 25690994343 + 25690994344.

It is an arithmetic number, because the mean of its divisors is an integer number (25690994344).

Almost surely, 2^51381988687 is an apocalyptic number.

51381988687 is a deficient number, since it is larger than the sum of its proper divisors (1).

51381988687 is an equidigital number, since it uses as much as digits as its factorization.

51381988687 is an evil number, because the sum of its binary digits is even.

The product of its digits is 23224320, while the sum is 64.

The spelling of 51381988687 in words is "fifty-one billion, three hundred eighty-one million, nine hundred eighty-eight thousand, six hundred eighty-seven".