51115651649 has 2 divisors, whose sum is σ = 51115651650. Its totient is φ = 51115651648.

The previous prime is 51115651579. The next prime is 51115651673. The reversal of 51115651649 is 94615651115.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 46517862400 + 4597789249 = 215680^2 + 67807^2 .

It is a cyclic number.

It is not a de Polignac number, because 51115651649 - 2¹² = 51115647553 is a prime.

It is a super-3 number, since 3×51115651649³ (a number of 33 digits) contains 333 as substring. Note that it is a super-d number also for d = 2.

It is not a weakly prime, because it can be changed into another prime (51115651049) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 25557825824 + 25557825825.

It is an arithmetic number, because the mean of its divisors is an integer number (25557825825).

Almost surely, 2^51115651649 is an apocalyptic number.

It is an amenable number.

51115651649 is a deficient number, since it is larger than the sum of its proper divisors (1).

51115651649 is an equidigital number, since it uses as much as digits as its factorization.

51115651649 is an evil number, because the sum of its binary digits is even.

The product of its digits is 162000, while the sum is 44.

The spelling of 51115651649 in words is "fifty-one billion, one hundred fifteen million, six hundred fifty-one thousand, six hundred forty-nine".