646515462453521 has 2 divisors, whose sum is σ = 646515462453522. Its totient is φ = 646515462453520.

The previous prime is 646515462453401. The next prime is 646515462453527. The reversal of 646515462453521 is 125354264515646.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 615382287610000 + 31133174843521 = 24806900^2 + 5579711^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-646515462453521 is a prime.

It is not a weakly prime, because it can be changed into another prime (646515462453527) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 323257731226760 + 323257731226761.

It is an arithmetic number, because the mean of its divisors is an integer number (323257731226761).

Almost surely, 2^{646515462453521} is an apocalyptic number.

It is an amenable number.

646515462453521 is a deficient number, since it is larger than the sum of its proper divisors (1).

646515462453521 is an equidigital number, since it uses as much as digits as its factorization.

646515462453521 is an evil number, because the sum of its binary digits is even.

The product of its digits is 103680000, while the sum is 59.

The spelling of 646515462453521 in words is "six hundred forty-six trillion, five hundred fifteen billion, four hundred sixty-two million, four hundred fifty-three thousand, five hundred twenty-one".