689905905 has 16 divisors (see below), whose sum is σ = 1188761280. Its totient is φ = 339645888.

The previous prime is 689905873. The next prime is 689905919. The reversal of 689905905 is 509509986.

It is not a de Polignac number, because 689905905 - 2⁵ = 689905873 is a prime.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 1768795 + ... + 1769184.

It is an arithmetic number, because the mean of its divisors is an integer number (74297580).

Almost surely, 2^689905905 is an apocalyptic number.

689905905 is a gapful number since it is divisible by the number (65) formed by its first and last digit.

It is an amenable number.

689905905 is a deficient number, since it is larger than the sum of its proper divisors (498855375).

689905905 is a wasteful number, since it uses less digits than its factorization.

689905905 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3538000.

The product of its (nonzero) digits is 874800, while the sum is 51.

The square root of 689905905 is about 26266.0599443464. The cubic root of 689905905 is about 883.6154225047.

The spelling of 689905905 in words is "six hundred eighty-nine million, nine hundred five thousand, nine hundred five".