645944229504 has 512 divisors, whose sum is σ = 2259944640000. Its totient is φ = 181509672960.

The previous prime is 645944229487. The next prime is 645944229563. The reversal of 645944229504 is 405922449546.

It is a happy number.

645944229504 is a `hidden beast` number, since 6 + 4 + 5 + 94 + 42 + 2 + 9 + 504 = 666.

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

It is an unprimeable number.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 72305422 + ... + 72314354.

It is an arithmetic number, because the mean of its divisors is an integer number (4413954375).

Almost surely, 2^645944229504 is an apocalyptic number.

645944229504 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 645944229504, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1129972320000).

645944229504 is an abundant number, since it is smaller than the sum of its proper divisors (1614000410496).

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

645944229504 is an equidigital number, since it uses as much as digits as its factorization.

645944229504 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9038 (or 9006 counting only the distinct ones).

The product of its (nonzero) digits is 12441600, while the sum is 54.

The spelling of 645944229504 in words is "six hundred forty-five billion, nine hundred forty-four million, two hundred twenty-nine thousand, five hundred four".