644652063000 has 576 divisors, whose sum is σ = 2401784330400. Its totient is φ = 155838144000.

The previous prime is 644652062959. The next prime is 644652063017. The reversal of 644652063000 is 360256446.

644652063000 is a `hidden beast` number, since 6 + 446 + 5 + 206 + 3 + 0 + 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 an unprimeable number.

It is a polite number, since it can be written in 143 ways as a sum of consecutive naturals, for example, 554300419 + ... + 554301581.

Almost surely, 2^644652063000 is an apocalyptic number.

644652063000 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 644652063000, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1200892165200).

644652063000 is an abundant number, since it is smaller than the sum of its proper divisors (1757132267400).

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

644652063000 is a wasteful number, since it uses less digits than its factorization.

644652063000 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1721 (or 1693 counting only the distinct ones).

The product of its (nonzero) digits is 103680, while the sum is 36.

The spelling of 644652063000 in words is "six hundred forty-four billion, six hundred fifty-two million, sixty-three thousand".