661626331627 has 2 divisors, whose sum is σ = 661626331628. Its totient is φ = 661626331626.

The previous prime is 661626331573. The next prime is 661626331651. The reversal of 661626331627 is 726133626166.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-661626331627 is a prime.

It is not a weakly prime, because it can be changed into another prime (661626311627) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 330813165813 + 330813165814.

It is an arithmetic number, because the mean of its divisors is an integer number (330813165814).

Almost surely, 2^661626331627 is an apocalyptic number.

661626331627 is a deficient number, since it is larger than the sum of its proper divisors (1).

661626331627 is an equidigital number, since it uses as much as digits as its factorization.

661626331627 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 1959552, while the sum is 49.

The spelling of 661626331627 in words is "six hundred sixty-one billion, six hundred twenty-six million, three hundred thirty-one thousand, six hundred twenty-seven".