64398809 has 4 divisors (see below), whose sum is σ = 67788240. Its totient is φ = 61009380.

The previous prime is 64398797. The next prime is 64398853. The reversal of 64398809 is 90889346.

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 not a de Polignac number, because 64398809 - 2⁸ = 64398553 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (64398109) 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, 1694687 + ... + 1694724.

It is an arithmetic number, because the mean of its divisors is an integer number (16947060).

Almost surely, 2^64398809 is an apocalyptic number.

It is an amenable number.

64398809 is a deficient number, since it is larger than the sum of its proper divisors (3389431).

64398809 is a wasteful number, since it uses less digits than its factorization.

64398809 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3389430.

The product of its (nonzero) digits is 373248, while the sum is 47.

The square root of 64398809 is about 8024.8868527849. The cubic root of 64398809 is about 400.8291322451.

The spelling of 64398809 in words is "sixty-four million, three hundred ninety-eight thousand, eight hundred nine".