691013945 has 16 divisors (see below), whose sum is σ = 877314240. Its totient is φ = 521043264.

The previous prime is 691013933. The next prime is 691013951. The reversal of 691013945 is 549310196.

It is a cyclic number.

It is not a de Polignac number, because 691013945 - 2⁴ = 691013929 is a prime.

It is a Curzon number.

It is a junction number, because it is equal to n+sod(n) for n = 691013899 and 691013908.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 254 + ... + 37176.

It is an arithmetic number, because the mean of its divisors is an integer number (54832140).

Almost surely, 2^691013945 is an apocalyptic number.

It is an amenable number.

691013945 is a deficient number, since it is larger than the sum of its proper divisors (186300295).

691013945 is a wasteful number, since it uses less digits than its factorization.

691013945 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 37144.

The product of its (nonzero) digits is 29160, while the sum is 38.

The square root of 691013945 is about 26287.1441012522. The cubic root of 691013945 is about 884.0882200915.

The spelling of 691013945 in words is "six hundred ninety-one million, thirteen thousand, nine hundred forty-five".