689402409 has 4 divisors (see below), whose sum is σ = 919203216. Its totient is φ = 459601604.

The previous prime is 689402401. The next prime is 689402423. The reversal of 689402409 is 904204986.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 689402409 - 2³ = 689402401 is a prime.

It is not an unprimeable number, because it can be changed into a prime (689402401) 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, 114900399 + ... + 114900404.

It is an arithmetic number, because the mean of its divisors is an integer number (229800804).

Almost surely, 2^689402409 is an apocalyptic number.

It is an amenable number.

689402409 is a deficient number, since it is larger than the sum of its proper divisors (229800807).

689402409 is a wasteful number, since it uses less digits than its factorization.

689402409 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 229800806.

The product of its (nonzero) digits is 124416, while the sum is 42.

The square root of 689402409 is about 26256.4736588903. The cubic root of 689402409 is about 883.4004148732.

The spelling of 689402409 in words is "six hundred eighty-nine million, four hundred two thousand, four hundred nine".