691977629818 has 16 divisors (see below), whose sum is σ = 1060075923840. Its totient is φ = 338619337056.

The previous prime is 691977629801. The next prime is 691977629851. The reversal of 691977629818 is 818926779196.

It is an unprimeable number.

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 7 ways as a sum of consecutive naturals, for example, 6723793 + ... + 6825931.

It is an arithmetic number, because the mean of its divisors is an integer number (66254745240).

Almost surely, 2^691977629818 is an apocalyptic number.

691977629818 is a deficient number, since it is larger than the sum of its proper divisors (368098294022).

691977629818 is a wasteful number, since it uses less digits than its factorization.

691977629818 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 174261.

The product of its digits is 164602368, while the sum is 73.

The spelling of 691977629818 in words is "six hundred ninety-one billion, nine hundred seventy-seven million, six hundred twenty-nine thousand, eight hundred eighteen".