691552394 has 12 divisors (see below), whose sum is σ = 1123261686. Its totient is φ = 319177872.

The previous prime is 691552391. The next prime is 691552409. The reversal of 691552394 is 493255196.

It can be written as a sum of positive squares in 3 ways, for example, as 403809025 + 287743369 = 20095^2 + 16963^2 .

It is not an unprimeable number, because it can be changed into a prime (691552391) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 1022669 + ... + 1023344.

Almost surely, 2^691552394 is an apocalyptic number.

691552394 is a deficient number, since it is larger than the sum of its proper divisors (431709292).

691552394 is a wasteful number, since it uses less digits than its factorization.

691552394 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2046041 (or 2046028 counting only the distinct ones).

The product of its digits is 291600, while the sum is 44.

The square root of 691552394 is about 26297.3837862248. The cubic root of 691552394 is about 884.3177923164.

The spelling of 691552394 in words is "six hundred ninety-one million, five hundred fifty-two thousand, three hundred ninety-four".