645476428800 has 1452 divisors, whose sum is σ = 2787806123056. Its totient is φ = 145118822400.

The previous prime is 645476428763. The next prime is 645476428859. The reversal of 645476428800 is 8824674546.

It is a happy number.

645476428800 is a `hidden beast` number, since 6 + 454 + 76 + 42 + 8 + 80 + 0 = 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 131 ways as a sum of consecutive naturals, for example, 10581580770 + ... + 10581580830.

Almost surely, 2^645476428800 is an apocalyptic number.

645476428800 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 645476428800, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1393903061528).

645476428800 is an abundant number, since it is smaller than the sum of its proper divisors (2142329694256).

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

645476428800 is an frugal number, since it uses more digits than its factorization.

645476428800 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 128 (or 78 counting only the distinct ones).

The product of its (nonzero) digits is 10321920, while the sum is 54.

The spelling of 645476428800 in words is "six hundred forty-five billion, four hundred seventy-six million, four hundred twenty-eight thousand, eight hundred".