645926400000 has 1560 divisors, whose sum is σ = 2787321287520. Its totient is φ = 145981440000.

The previous prime is 645926399969. The next prime is 645926400001. The reversal of 645926400000 is 4629546.

645926400000 is a `hidden beast` number, since 6 + 4 + 5 + 9 + 2 + 640 + 0 + 0 + 0 + 0 = 666.

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

It is not an unprimeable number, because it can be changed into a prime (645926400001) by changing a digit.

It is a polite number, since it can be written in 119 ways as a sum of consecutive naturals, for example, 7257599956 + ... + 7257600044.

Almost surely, 2^645926400000 is an apocalyptic number.

645926400000 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 645926400000, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1393660643760).

645926400000 is an abundant number, since it is smaller than the sum of its proper divisors (2141394887520).

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

645926400000 is an frugal number, since it uses more digits than its factorization.

645926400000 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 157 (or 106 counting only the distinct ones).

The product of its (nonzero) digits is 51840, while the sum is 36.

The spelling of 645926400000 in words is "six hundred forty-five billion, nine hundred twenty-six million, four hundred thousand".