691645613 has 8 divisors (see below), whose sum is σ = 704175360. Its totient is φ = 679142880.

The previous prime is 691645609. The next prime is 691645637. The reversal of 691645613 is 316546196.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 691645613 - 2² = 691645609 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (691645013) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 49028 + ... + 61538.

It is an arithmetic number, because the mean of its divisors is an integer number (88021920).

Almost surely, 2^691645613 is an apocalyptic number.

It is an amenable number.

691645613 is a deficient number, since it is larger than the sum of its proper divisors (12529747).

691645613 is a wasteful number, since it uses less digits than its factorization.

691645613 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 13507.

The product of its digits is 116640, while the sum is 41.

The square root of 691645613 is about 26299.1561271460. The cubic root of 691645613 is about 884.3575249128.

The spelling of 691645613 in words is "six hundred ninety-one million, six hundred forty-five thousand, six hundred thirteen".