644000226880 has 56 divisors (see below), whose sum is σ = 1533863644992. Its totient is φ = 257543296512.

The previous prime is 644000226851. The next prime is 644000226899. The reversal of 644000226880 is 88622000446.

644000226880 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a Harshad number since it is a multiple of its sum of digits (40).

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1246999 + ... + 1686121.

It is an arithmetic number, because the mean of its divisors is an integer number (27390422232).

Almost surely, 2^644000226880 is an apocalyptic number.

It is an amenable number.

644000226880 is an abundant number, since it is smaller than the sum of its proper divisors (889863418112).

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

644000226880 is a wasteful number, since it uses less digits than its factorization.

644000226880 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 443723 (or 443713 counting only the distinct ones).

The product of its (nonzero) digits is 147456, while the sum is 40.

The spelling of 644000226880 in words is "six hundred forty-four billion, two hundred twenty-six thousand, eight hundred eighty".