644995914 has 32 divisors (see below), whose sum is σ = 1328711040. Its totient is φ = 208579392.

The previous prime is 644995867. The next prime is 644995919. The reversal of 644995914 is 419599446.

It is not an unprimeable number, because it can be changed into a prime (644995919) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 75652 + ... + 83744.

It is an arithmetic number, because the mean of its divisors is an integer number (41522220).

Almost surely, 2^644995914 is an apocalyptic number.

644995914 is an abundant number, since it is smaller than the sum of its proper divisors (683715126).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

644995914 is a wasteful number, since it uses less digits than its factorization.

644995914 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 8494.

The product of its digits is 1399680, while the sum is 51.

The square root of 644995914 is about 25396.7697552267. The cubic root of 644995914 is about 864.0104352949.

The spelling of 644995914 in words is "six hundred forty-four million, nine hundred ninety-five thousand, nine hundred fourteen".