699371991 has 6 divisors (see below), whose sum is σ = 1010204000. Its totient is φ = 466247988.

The previous prime is 699371989. The next prime is 699371999. The reversal of 699371991 is 199173996.

It is not a de Polignac number, because 699371991 - 2¹ = 699371989 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 (699371999) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 38853991 + ... + 38854008.

Almost surely, 2^699371991 is an apocalyptic number.

699371991 is a deficient number, since it is larger than the sum of its proper divisors (310832009).

699371991 is a wasteful number, since it uses less digits than its factorization.

699371991 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 77708005 (or 77708002 counting only the distinct ones).

The product of its digits is 826686, while the sum is 54.

The square root of 699371991 is about 26445.6421929966. The cubic root of 699371991 is about 887.6383929130.

The spelling of 699371991 in words is "six hundred ninety-nine million, three hundred seventy-one thousand, nine hundred ninety-one".