691994402 has 54 divisors (see below), whose sum is σ = 1217824209. Its totient is φ = 294639840.

The previous prime is 691994363. The next prime is 691994467. The reversal of 691994402 is 204499196.

It can be written as a sum of positive squares in 2 ways, for example, as 618566641 + 73427761 = 24871^2 + 8569^2 .

It is an ABA number since it can be written as A⋅B^A, here for A=2, B=18601.

It is an unprimeable number.

It is a polite number, since it can be written in 26 ways as a sum of consecutive naturals, for example, 7775174 + ... + 7775262.

Almost surely, 2^691994402 is an apocalyptic number.

691994402 is a deficient number, since it is larger than the sum of its proper divisors (525829807).

691994402 is a wasteful number, since it uses less digits than its factorization.

691994402 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 240 (or 121 counting only the distinct ones).

The product of its (nonzero) digits is 139968, while the sum is 44.

The square root of 691994402 is about 26305.7864737019. The cubic root of 691994402 is about 884.5061570714.

The spelling of 691994402 in words is "six hundred ninety-one million, nine hundred ninety-four thousand, four hundred two".