645987312000 has 512 divisors, whose sum is σ = 2408892220800. Its totient is φ = 172253952000.

The previous prime is 645987311951. The next prime is 645987312001. The reversal of 645987312000 is 213789546.

645987312000 is a `hidden beast` number, since 6 + 4 + 598 + 7 + 31 + 20 + 0 + 0 = 666.

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

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (645987312001) by changing a digit.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 34982770 + ... + 35001230.

It is a 1-persistent number, because it is pandigital, but 2⋅645987312000 = 1291974624000 is not.

Almost surely, 2^645987312000 is an apocalyptic number.

645987312000 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 645987312000, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1204446110400).

645987312000 is an abundant number, since it is smaller than the sum of its proper divisors (1762904908800).

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

645987312000 is an frugal number, since it uses more digits than its factorization.

645987312000 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 18511 (or 18471 counting only the distinct ones).

The product of its (nonzero) digits is 362880, while the sum is 45.

The spelling of 645987312000 in words is "six hundred forty-five billion, nine hundred eighty-seven million, three hundred twelve thousand".