644167104 has 112 divisors (see below), whose sum is σ = 2010802176. Its totient is φ = 178099200.

The previous prime is 644167103. The next prime is 644167109. The reversal of 644167104 is 401761446.

It is a tau number, because it is divible by the number of its divisors (112).

It is a hoax number, since the sum of its digits (33) coincides with the sum of the digits of its distinct prime factors.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (644167103) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 33934 + ... + 49394.

Almost surely, 2^644167104 is an apocalyptic number.

644167104 is a gapful number since it is divisible by the number (64) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 644167104, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1005401088).

644167104 is an abundant number, since it is smaller than the sum of its proper divisors (1366635072).

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

644167104 is a wasteful number, since it uses less digits than its factorization.

644167104 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 15514 (or 15504 counting only the distinct ones).

The product of its (nonzero) digits is 16128, while the sum is 33.

The square root of 644167104 is about 25380.4472773826. The cubic root of 644167104 is about 863.6401965494.

The spelling of 644167104 in words is "six hundred forty-four million, one hundred sixty-seven thousand, one hundred four".