689689691 has 4 divisors (see below), whose sum is σ = 696799992. Its totient is φ = 682579392.

The previous prime is 689689667. The next prime is 689689697. The reversal of 689689691 is 196986986.

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

It is a cyclic number.

It is not a de Polignac number, because 689689691 - 2¹⁸ = 689427547 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (689689697) 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, 3555005 + ... + 3555198.

It is an arithmetic number, because the mean of its divisors is an integer number (174199998).

Almost surely, 2^689689691 is an apocalyptic number.

689689691 is a deficient number, since it is larger than the sum of its proper divisors (7110301).

689689691 is an equidigital number, since it uses as much as digits as its factorization.

689689691 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7110300.

The product of its digits is 10077696, while the sum is 62.

The square root of 689689691 is about 26261.9437780222. The cubic root of 689689691 is about 883.5231055741.

The spelling of 689689691 in words is "six hundred eighty-nine million, six hundred eighty-nine thousand, six hundred ninety-one".