644168114478 has 32 divisors (see below), whose sum is σ = 1635982513920. Its totient is φ = 184048032600.

The previous prime is 644168114477. The next prime is 644168114483. The reversal of 644168114478 is 874411861446.

644168114478 is a `hidden beast` number, since 6 + 4 + 4 + 168 + 1 + 1 + 4 + 478 = 666.

It is a Harshad number since it is a multiple of its sum of digits (54).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (644168114477) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 852073848 + ... + 852074603.

It is an arithmetic number, because the mean of its divisors is an integer number (51124453560).

Almost surely, 2^644168114478 is an apocalyptic number.

644168114478 is an abundant number, since it is smaller than the sum of its proper divisors (991814399442).

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

644168114478 is a wasteful number, since it uses less digits than its factorization.

644168114478 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1704148469 (or 1704148463 counting only the distinct ones).

The product of its digits is 4128768, while the sum is 54.

The spelling of 644168114478 in words is "six hundred forty-four billion, one hundred sixty-eight million, one hundred fourteen thousand, four hundred seventy-eight".