689909986 has 4 divisors (see below), whose sum is σ = 1034864982. Its totient is φ = 344954992.

The previous prime is 689909981. The next prime is 689909989.

689909986 is nontrivially palindromic in base 10.

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

It can be written as a sum of positive squares in only one way, i.e., 662084361 + 27825625 = 25731^2 + 5275^2 .

It is not an unprimeable number, because it can be changed into a prime (689909981) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 172477495 + ... + 172477498.

Almost surely, 2^689909986 is an apocalyptic number.

689909986 is a deficient number, since it is larger than the sum of its proper divisors (344954996).

689909986 is a wasteful number, since it uses less digits than its factorization.

689909986 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 344954995.

The product of its (nonzero) digits is 15116544, while the sum is 64.

The square root of 689909986 is about 26266.1376300361. The cubic root of 689909986 is about 883.6171647845.

The spelling of 689909986 in words is "six hundred eighty-nine million, nine hundred nine thousand, nine hundred eighty-six".