691379371 has 4 divisors (see below), whose sum is σ = 691506144. Its totient is φ = 691252600.

The previous prime is 691379357. The next prime is 691379389. The reversal of 691379371 is 173973196.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 691379371 - 2¹⁵ = 691346603 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (691371371) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 54820 + ... + 66241.

It is an arithmetic number, because the mean of its divisors is an integer number (172876536).

Almost surely, 2^691379371 is an apocalyptic number.

691379371 is a deficient number, since it is larger than the sum of its proper divisors (126773).

691379371 is a wasteful number, since it uses less digits than its factorization.

691379371 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 126772.

The product of its digits is 214326, while the sum is 46.

The square root of 691379371 is about 26294.0938425343. The cubic root of 691379371 is about 884.2440355141.

The spelling of 691379371 in words is "six hundred ninety-one million, three hundred seventy-nine thousand, three hundred seventy-one".