64689409 has 4 divisors (see below), whose sum is σ = 67502016. Its totient is φ = 61876804.

The previous prime is 64689407. The next prime is 64689451. The reversal of 64689409 is 90498646.

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 64689409 - 2¹ = 64689407 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (64689407) 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, 1406269 + ... + 1406314.

It is an arithmetic number, because the mean of its divisors is an integer number (16875504).

Almost surely, 2^64689409 is an apocalyptic number.

It is an amenable number.

64689409 is a deficient number, since it is larger than the sum of its proper divisors (2812607).

64689409 is a wasteful number, since it uses less digits than its factorization.

64689409 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2812606.

The product of its (nonzero) digits is 373248, while the sum is 46.

The square root of 64689409 is about 8042.9726469757. The cubic root of 64689409 is about 401.4311422231.

The spelling of 64689409 in words is "sixty-four million, six hundred eighty-nine thousand, four hundred nine".