51660505651 has 2 divisors, whose sum is σ = 51660505652. Its totient is φ = 51660505650.

The previous prime is 51660505649. The next prime is 51660505693. The reversal of 51660505651 is 15650506615.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 51660505651 - 2¹ = 51660505649 is a prime.

Together with 51660505649, it forms a pair of twin primes.

It is not a weakly prime, because it can be changed into another prime (51660505151) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 25830252825 + 25830252826.

It is an arithmetic number, because the mean of its divisors is an integer number (25830252826).

Almost surely, 2^51660505651 is an apocalyptic number.

51660505651 is a deficient number, since it is larger than the sum of its proper divisors (1).

51660505651 is an equidigital number, since it uses as much as digits as its factorization.

51660505651 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 135000, while the sum is 40.

The spelling of 51660505651 in words is "fifty-one billion, six hundred sixty million, five hundred five thousand, six hundred fifty-one".