644146430400 has 1344 divisors, whose sum is σ = 2647236280320. Its totient is φ = 151027200000.

The previous prime is 644146430387. The next prime is 644146430401. The reversal of 644146430400 is 4034641446.

644146430400 is a `hidden beast` number, since 6 + 4 + 4 + 1 + 4 + 643 + 0 + 4 + 0 + 0 = 666.

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

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (644146430401) by changing a digit.

It is a polite number, since it can be written in 191 ways as a sum of consecutive naturals, for example, 3372494305 + ... + 3372494495.

Almost surely, 2^644146430400 is an apocalyptic number.

644146430400 is a gapful number since it is divisible by the number (60) 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 644146430400, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1323618140160).

644146430400 is an abundant number, since it is smaller than the sum of its proper divisors (2003089849920).

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

644146430400 is a wasteful number, since it uses less digits than its factorization.

644146430400 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 431 (or 410 counting only the distinct ones).

The product of its (nonzero) digits is 110592, while the sum is 36.

The spelling of 644146430400 in words is "six hundred forty-four billion, one hundred forty-six million, four hundred thirty thousand, four hundred".