691313439 has 16 divisors (see below), whose sum is σ = 960007680. Its totient is φ = 442098720.

The previous prime is 691313419. The next prime is 691313473. The reversal of 691313439 is 934313196.

It is not a de Polignac number, because 691313439 - 2⁵ = 691313407 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 691313397 and 691313406.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (691313419) 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, 35979 + ... + 51740.

It is an arithmetic number, because the mean of its divisors is an integer number (60000480).

Almost surely, 2^691313439 is an apocalyptic number.

691313439 is a deficient number, since it is larger than the sum of its proper divisors (268694241).

691313439 is a wasteful number, since it uses less digits than its factorization.

691313439 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 87830.

The product of its digits is 52488, while the sum is 39.

The square root of 691313439 is about 26292.8400710155. The cubic root of 691313439 is about 884.2159265705.

The spelling of 691313439 in words is "six hundred ninety-one million, three hundred thirteen thousand, four hundred thirty-nine".