644326254 has 96 divisors (see below), whose sum is σ = 1649872224. Its totient is φ = 179159040.

The previous prime is 644326237. The next prime is 644326343. The reversal of 644326254 is 452623446.

644326254 is a `hidden beast` number, since 644 + 3 + 2 + 6 + 2 + 5 + 4 = 666.

It is a congruent number.

It is an unprimeable number.

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 47 ways as a sum of consecutive naturals, for example, 496134 + ... + 497430.

It is an arithmetic number, because the mean of its divisors is an integer number (17186169).

Almost surely, 2^644326254 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 644326254, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (824936112).

644326254 is an abundant number, since it is smaller than the sum of its proper divisors (1005545970).

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

644326254 is a wasteful number, since it uses less digits than its factorization.

644326254 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1522 (or 1519 counting only the distinct ones).

The product of its digits is 138240, while the sum is 36.

The square root of 644326254 is about 25383.5823712887. The cubic root of 644326254 is about 863.7113152692.

The spelling of 644326254 in words is "six hundred forty-four million, three hundred twenty-six thousand, two hundred fifty-four".