691806440631 has 16 divisors (see below), whose sum is σ = 974109862656. Its totient is φ = 435836846016.

The previous prime is 691806440629. The next prime is 691806440641. The reversal of 691806440631 is 136044608196.

It is not a de Polignac number, because 691806440631 - 2¹ = 691806440629 is a prime.

It is a super-2 number, since 2×691806440631² (a number of 24 digits) contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (691806440641) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 60392950 + ... + 60404403.

It is an arithmetic number, because the mean of its divisors is an integer number (60881866416).

Almost surely, 2^691806440631 is an apocalyptic number.

691806440631 is a deficient number, since it is larger than the sum of its proper divisors (282303422025).

691806440631 is a wasteful number, since it uses less digits than its factorization.

691806440631 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 120797462.

The product of its (nonzero) digits is 746496, while the sum is 48.

The spelling of 691806440631 in words is "six hundred ninety-one billion, eight hundred six million, four hundred forty thousand, six hundred thirty-one".