51497979749 has 2 divisors, whose sum is σ = 51497979750. Its totient is φ = 51497979748.

The previous prime is 51497979737. The next prime is 51497979781. The reversal of 51497979749 is 94797979415.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 37024686724 + 14473293025 = 192418^2 + 120305^2 .

It is a cyclic number.

It is not a de Polignac number, because 51497979749 - 2⁴ = 51497979733 is a prime.

It is a Sophie Germain prime.

It is a Curzon number.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (51497949749) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 25748989874 + 25748989875.

It is an arithmetic number, because the mean of its divisors is an integer number (25748989875).

Almost surely, 2^51497979749 is an apocalyptic number.

It is an amenable number.

51497979749 is a deficient number, since it is larger than the sum of its proper divisors (1).

51497979749 is an equidigital number, since it uses as much as digits as its factorization.

51497979749 is an evil number, because the sum of its binary digits is even.

The product of its digits is 180033840, while the sum is 71.

The spelling of 51497979749 in words is "fifty-one billion, four hundred ninety-seven million, nine hundred seventy-nine thousand, seven hundred forty-nine".