644107464 has 384 divisors, whose sum is σ = 2436295680. Its totient is φ = 153964800.

The previous prime is 644107459. The next prime is 644107483. The reversal of 644107464 is 464701446.

644107464 is a `hidden beast` number, since 644 + 1 + 0 + 7 + 4 + 6 + 4 = 666.

It is a super-2 number, since 2×644107464² = 829748850361022592, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a zygodrome in base 3.

It is an unprimeable number.

It is a polite number, since it can be written in 95 ways as a sum of consecutive naturals, for example, 1945779 + ... + 1946109.

It is an arithmetic number, because the mean of its divisors is an integer number (6344520).

Almost surely, 2^644107464 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 644107464, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1218147840).

644107464 is an abundant number, since it is smaller than the sum of its proper divisors (1792188216).

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

644107464 is a wasteful number, since it uses less digits than its factorization.

644107464 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 383 (or 367 counting only the distinct ones).

The product of its (nonzero) digits is 64512, while the sum is 36.

The square root of 644107464 is about 25379.2723299940. The cubic root of 644107464 is about 863.6135424454.

The spelling of 644107464 in words is "six hundred forty-four million, one hundred seven thousand, four hundred sixty-four".