644002774 has 8 divisors (see below), whose sum is σ = 969569568. Its totient is φ = 320812920.

The previous prime is 644002771. The next prime is 644002781. The reversal of 644002774 is 477200446.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (644002771) 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, 593557 + ... + 594640.

It is an arithmetic number, because the mean of its divisors is an integer number (121196196).

Almost surely, 2^644002774 is an apocalyptic number.

644002774 is a deficient number, since it is larger than the sum of its proper divisors (325566794).

644002774 is a wasteful number, since it uses less digits than its factorization.

644002774 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1188470.

The product of its (nonzero) digits is 37632, while the sum is 34.

The square root of 644002774 is about 25377.2097362969. The cubic root of 644002774 is about 863.5667507708.

The spelling of 644002774 in words is "six hundred forty-four million, two thousand, seven hundred seventy-four".