689997655 has 8 divisors (see below), whose sum is σ = 828162000. Its totient is φ = 551888256.

The previous prime is 689997629. The next prime is 689997661. The reversal of 689997655 is 556799986.

It is a happy number.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 689997655 - 2⁷ = 689997527 is a prime.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 22671 + ... + 43519.

It is an arithmetic number, because the mean of its divisors is an integer number (103520250).

Almost surely, 2^689997655 is an apocalyptic number.

689997655 is a deficient number, since it is larger than the sum of its proper divisors (138164345).

689997655 is a wasteful number, since it uses less digits than its factorization.

689997655 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 27473.

The product of its digits is 36741600, while the sum is 64.

The square root of 689997655 is about 26267.8064367773. The cubic root of 689997655 is about 883.6545911898.

The spelling of 689997655 in words is "six hundred eighty-nine million, nine hundred ninety-seven thousand, six hundred fifty-five".