644652254 has 48 divisors (see below), whose sum is σ = 1067673600. Its totient is φ = 291075120.

The previous prime is 644652251. The next prime is 644652277. The reversal of 644652254 is 452256446.

It is a Harshad number since it is a multiple of its sum of digits (38).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (644652251) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 4637717 + ... + 4637855.

It is an arithmetic number, because the mean of its divisors is an integer number (22243200).

Almost surely, 2^644652254 is an apocalyptic number.

644652254 is a deficient number, since it is larger than the sum of its proper divisors (423021346).

644652254 is a wasteful number, since it uses less digits than its factorization.

644652254 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 349 (or 318 counting only the distinct ones).

The product of its digits is 230400, while the sum is 38.

The square root of 644652254 is about 25390.0030326899. The cubic root of 644652254 is about 863.8569570220.

The spelling of 644652254 in words is "six hundred forty-four million, six hundred fifty-two thousand, two hundred fifty-four".