691138707 has 48 divisors (see below), whose sum is σ = 1136309760. Its totient is φ = 365333760.

The previous prime is 691138703. The next prime is 691138711. The reversal of 691138707 is 707831196.

It is an interprime number because it is at equal distance from previous prime (691138703) and next prime (691138711).

It is not a de Polignac number, because 691138707 - 2² = 691138703 is a prime.

It is not an unprimeable number, because it can be changed into a prime (691138703) by changing a digit.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 463419 + ... + 464907.

It is an arithmetic number, because the mean of its divisors is an integer number (23673120).

Almost surely, 2^691138707 is an apocalyptic number.

691138707 is a deficient number, since it is larger than the sum of its proper divisors (445171053).

691138707 is a wasteful number, since it uses less digits than its factorization.

691138707 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1584 (or 1553 counting only the distinct ones).

The product of its (nonzero) digits is 63504, while the sum is 42.

The square root of 691138707 is about 26289.5170552827. The cubic root of 691138707 is about 884.1414240235.

The spelling of 691138707 in words is "six hundred ninety-one million, one hundred thirty-eight thousand, seven hundred seven".