691861213899 has 12 divisors (see below), whose sum is σ = 1026364684176. Its totient is φ = 448774841232.

The previous prime is 691861213877. The next prime is 691861213913. The reversal of 691861213899 is 998312168196.

691861213899 is a `hidden beast` number, since 6 + 9 + 1 + 8 + 612 + 1 + 3 + 8 + 9 + 9 = 666.

It is not a de Polignac number, because 691861213899 - 2⁵ = 691861213867 is a prime.

It is not an unprimeable number, because it can be changed into a prime (691861213499) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 1038830319 + ... + 1038830984.

It is an arithmetic number, because the mean of its divisors is an integer number (85530390348).

Almost surely, 2^691861213899 is an apocalyptic number.

691861213899 is a deficient number, since it is larger than the sum of its proper divisors (334503470277).

691861213899 is a wasteful number, since it uses less digits than its factorization.

691861213899 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2077661346 (or 2077661343 counting only the distinct ones).

The product of its digits is 10077696, while the sum is 63.

The spelling of 691861213899 in words is "six hundred ninety-one billion, eight hundred sixty-one million, two hundred thirteen thousand, eight hundred ninety-nine".