689899391 has 4 divisors (see below), whose sum is σ = 690818784. Its totient is φ = 688980000.

The previous prime is 689899349. The next prime is 689899393. The reversal of 689899391 is 193998986.

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

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-689899391 is a prime.

It is a super-2 number, since 2×689899391² = 951922339404341762, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (689899393) 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, 458570 + ... + 460071.

It is an arithmetic number, because the mean of its divisors is an integer number (172704696).

Almost surely, 2^689899391 is an apocalyptic number.

689899391 is a deficient number, since it is larger than the sum of its proper divisors (919393).

689899391 is an equidigital number, since it uses as much as digits as its factorization.

689899391 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 919392.

The product of its digits is 7558272, while the sum is 62.

The square root of 689899391 is about 26265.9359437276. The cubic root of 689899391 is about 883.6126415028.

The spelling of 689899391 in words is "six hundred eighty-nine million, eight hundred ninety-nine thousand, three hundred ninety-one".