51465913381 has 2 divisors, whose sum is σ = 51465913382. Its totient is φ = 51465913380.

The previous prime is 51465913379. The next prime is 51465913391. The reversal of 51465913381 is 18331956415.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 31247632900 + 20218280481 = 176770^2 + 142191^2 .

It is a cyclic number.

It is not a de Polignac number, because 51465913381 - 2¹ = 51465913379 is a prime.

It is a super-2 number, since 2×51465913381² (a number of 22 digits) contains 22 as substring.

Together with 51465913379, it forms a pair of twin primes.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (51465913391) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 25732956690 + 25732956691.

It is an arithmetic number, because the mean of its divisors is an integer number (25732956691).

Almost surely, 2^51465913381 is an apocalyptic number.

It is an amenable number.

51465913381 is a deficient number, since it is larger than the sum of its proper divisors (1).

51465913381 is an equidigital number, since it uses as much as digits as its factorization.

51465913381 is an evil number, because the sum of its binary digits is even.

The product of its digits is 388800, while the sum is 46.

The spelling of 51465913381 in words is "fifty-one billion, four hundred sixty-five million, nine hundred thirteen thousand, three hundred eighty-one".