691379157 has 16 divisors (see below), whose sum is σ = 1063761920. Its totient is φ = 391236912.

The previous prime is 691379153. The next prime is 691379159. The reversal of 691379157 is 751973196.

It is not a de Polignac number, because 691379157 - 2² = 691379153 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 (691379153) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 157657 + ... + 161982.

It is an arithmetic number, because the mean of its divisors is an integer number (66485120).

Almost surely, 2^691379157 is an apocalyptic number.

It is an amenable number.

691379157 is a deficient number, since it is larger than the sum of its proper divisors (372382763).

691379157 is a wasteful number, since it uses less digits than its factorization.

691379157 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 319752.

The product of its digits is 357210, while the sum is 48.

The square root of 691379157 is about 26294.0897731791. The cubic root of 691379157 is about 884.2439442818.

The spelling of 691379157 in words is "six hundred ninety-one million, three hundred seventy-nine thousand, one hundred fifty-seven".