645235718400 has 1728 divisors, whose sum is σ = 2993416742400. Its totient is φ = 132338810880.

The previous prime is 645235718357. The next prime is 645235718411. The reversal of 645235718400 is 4817532546.

645235718400 is a `hidden beast` number, since 6 + 4 + 5 + 235 + 7 + 1 + 8 + 400 = 666.

It is a tau number, because it is divible by the number of its divisors (1728).

It is a Harshad number since it is a multiple of its sum of digits (45).

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 191 ways as a sum of consecutive naturals, for example, 581817046 + ... + 581818154.

Almost surely, 2^645235718400 is an apocalyptic number.

645235718400 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 645235718400, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1496708371200).

645235718400 is an abundant number, since it is smaller than the sum of its proper divisors (2348181024000).

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

645235718400 is a wasteful number, since it uses less digits than its factorization.

645235718400 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1201 (or 1176 counting only the distinct ones).

The product of its (nonzero) digits is 806400, while the sum is 45.

The spelling of 645235718400 in words is "six hundred forty-five billion, two hundred thirty-five million, seven hundred eighteen thousand, four hundred".