691627639961 has 4 divisors (see below), whose sum is σ = 713938209024. Its totient is φ = 669317070900.

The previous prime is 691627639939. The next prime is 691627640069. The reversal of 691627639961 is 169936726196.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 691627639961 - 2⁶ = 691627639897 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (691627639561) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 11155284485 + ... + 11155284546.

It is an arithmetic number, because the mean of its divisors is an integer number (178484552256).

Almost surely, 2^691627639961 is an apocalyptic number.

It is an amenable number.

691627639961 is a deficient number, since it is larger than the sum of its proper divisors (22310569063).

691627639961 is a wasteful number, since it uses less digits than its factorization.

691627639961 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 22310569062.

The product of its digits is 39680928, while the sum is 65.

The spelling of 691627639961 in words is "six hundred ninety-one billion, six hundred twenty-seven million, six hundred thirty-nine thousand, nine hundred sixty-one".