691963139805 has 16 divisors (see below), whose sum is σ = 1265304027264. Its totient is φ = 316326006720.

The previous prime is 691963139789. The next prime is 691963139807. The reversal of 691963139805 is 508931369196.

It is not a de Polignac number, because 691963139805 - 2⁴ = 691963139789 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (691963139807) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 3295062466 + ... + 3295062675.

It is an arithmetic number, because the mean of its divisors is an integer number (79081501704).

Almost surely, 2^691963139805 is an apocalyptic number.

It is an amenable number.

691963139805 is a deficient number, since it is larger than the sum of its proper divisors (573340887459).

691963139805 is a wasteful number, since it uses less digits than its factorization.

691963139805 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6590125156.

The product of its (nonzero) digits is 9447840, while the sum is 60.

The spelling of 691963139805 in words is "six hundred ninety-one billion, nine hundred sixty-three million, one hundred thirty-nine thousand, eight hundred five".