645412860 has 84 divisors (see below), whose sum is σ = 2032166808. Its totient is φ = 172106208.

The previous prime is 645412849. The next prime is 645412861. The reversal of 645412860 is 68214546.

645412860 is a `hidden beast` number, since 645 + 4 + 1 + 2 + 8 + 6 + 0 = 666.

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

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (645412861) by changing a digit.

It is a polite number, since it can be written in 27 ways as a sum of consecutive naturals, for example, 7554 + ... + 36713.

It is an arithmetic number, because the mean of its divisors is an integer number (24192462).

Almost surely, 2^645412860 is an apocalyptic number.

645412860 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 645412860, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1016083404).

645412860 is an abundant number, since it is smaller than the sum of its proper divisors (1386753948).

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

645412860 is a wasteful number, since it uses less digits than its factorization.

645412860 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 44294 (or 44277 counting only the distinct ones).

The product of its (nonzero) digits is 46080, while the sum is 36.

The square root of 645412860 is about 25404.9770714323. The cubic root of 645412860 is about 864.1965698581.

The spelling of 645412860 in words is "six hundred forty-five million, four hundred twelve thousand, eight hundred sixty".