691678952731 has 16 divisors (see below), whose sum is σ = 755766085984. Its totient is φ = 629161945344.

The previous prime is 691678952729. The next prime is 691678952743. The reversal of 691678952731 is 137259876196.

It is a cyclic number.

It is not a de Polignac number, because 691678952731 - 2¹ = 691678952729 is a prime.

It is a super-2 number, since 2×691678952731² (a number of 24 digits) contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (691678952431) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 733780 + ... + 1386286.

It is an arithmetic number, because the mean of its divisors is an integer number (47235380374).

Almost surely, 2^691678952731 is an apocalyptic number.

691678952731 is a deficient number, since it is larger than the sum of its proper divisors (64087133253).

691678952731 is a wasteful number, since it uses less digits than its factorization.

691678952731 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 653710.

The product of its digits is 34292160, while the sum is 64.

The spelling of 691678952731 in words is "six hundred ninety-one billion, six hundred seventy-eight million, nine hundred fifty-two thousand, seven hundred thirty-one".