689131955 has 4 divisors (see below), whose sum is σ = 826958352. Its totient is φ = 551305560.

The previous prime is 689131939. The next prime is 689131973. The reversal of 689131955 is 559131986.

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

It is not a de Polignac number, because 689131955 - 2⁴ = 689131939 is a prime.

It is a Duffinian number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 68913191 + ... + 68913200.

It is an arithmetic number, because the mean of its divisors is an integer number (206739588).

Almost surely, 2^689131955 is an apocalyptic number.

689131955 is a deficient number, since it is larger than the sum of its proper divisors (137826397).

689131955 is a wasteful number, since it uses less digits than its factorization.

689131955 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 137826396.

The product of its digits is 291600, while the sum is 47.

The square root of 689131955 is about 26251.3229190454. The cubic root of 689131955 is about 883.2848798231.

The spelling of 689131955 in words is "six hundred eighty-nine million, one hundred thirty-one thousand, nine hundred fifty-five".