691319440631 has 2 divisors, whose sum is σ = 691319440632. Its totient is φ = 691319440630.

The previous prime is 691319440597. The next prime is 691319440697. The reversal of 691319440631 is 136044913196.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 691319440631 - 2³⁴ = 674139571447 is a prime.

It is a super-2 number, since 2×691319440631² (a number of 24 digits) contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (691319443631) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 345659720315 + 345659720316.

It is an arithmetic number, because the mean of its divisors is an integer number (345659720316).

Almost surely, 2^691319440631 is an apocalyptic number.

691319440631 is a deficient number, since it is larger than the sum of its proper divisors (1).

691319440631 is an equidigital number, since it uses as much as digits as its factorization.

691319440631 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 419904, while the sum is 47.

The spelling of 691319440631 in words is "six hundred ninety-one billion, three hundred nineteen million, four hundred forty thousand, six hundred thirty-one".