645815183900 has 144 divisors (see below), whose sum is σ = 1463250096000. Its totient is φ = 247101254400.

The previous prime is 645815183899. The next prime is 645815183969. The reversal of 645815183900 is 9381518546.

645815183900 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a Harshad number since it is a multiple of its sum of digits (50).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 326333111 + ... + 326335089.

It is an arithmetic number, because the mean of its divisors is an integer number (10161459000).

Almost surely, 2^645815183900 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 645815183900, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (731625048000).

645815183900 is an abundant number, since it is smaller than the sum of its proper divisors (817434912100).

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

645815183900 is a wasteful number, since it uses less digits than its factorization.

645815183900 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3012 (or 3005 counting only the distinct ones).

The product of its (nonzero) digits is 1036800, while the sum is 50.

The spelling of 645815183900 in words is "six hundred forty-five billion, eight hundred fifteen million, one hundred eighty-three thousand, nine hundred".