691431691 has 16 divisors (see below), whose sum is σ = 723201408. Its totient is φ = 660441600.

The previous prime is 691431677. The next prime is 691431707. The reversal of 691431691 is 196134196.

It is a happy number.

It is a cyclic number.

It is not a de Polignac number, because 691431691 - 2⁷ = 691431563 is a prime.

It is not an unprimeable number, because it can be changed into a prime (691431991) 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, 758526 + ... + 759436.

It is an arithmetic number, because the mean of its divisors is an integer number (45200088).

Almost surely, 2^691431691 is an apocalyptic number.

691431691 is a deficient number, since it is larger than the sum of its proper divisors (31769717).

691431691 is a wasteful number, since it uses less digits than its factorization.

691431691 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1302.

The product of its digits is 34992, while the sum is 40.

The square root of 691431691 is about 26295.0887239423. The cubic root of 691431691 is about 884.2663399502.

The spelling of 691431691 in words is "six hundred ninety-one million, four hundred thirty-one thousand, six hundred ninety-one".