645099000 has 512 divisors, whose sum is σ = 2641766400. Its totient is φ = 127180800.

The previous prime is 645098999. The next prime is 645099011. The reversal of 645099000 is 990546.

It is a happy number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 127 ways as a sum of consecutive naturals, for example, 4640931 + ... + 4641069.

It is an arithmetic number, because the mean of its divisors is an integer number (5159700).

Almost surely, 2^645099000 is an apocalyptic number.

645099000 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 645099000, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1320883200).

645099000 is an abundant number, since it is smaller than the sum of its proper divisors (1996667400).

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

645099000 is a wasteful number, since it uses less digits than its factorization.

645099000 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 200 (or 186 counting only the distinct ones).

The product of its (nonzero) digits is 9720, while the sum is 33.

The square root of 645099000 is about 25398.7991842134. The cubic root of 645099000 is about 864.0564627881.

The spelling of 645099000 in words is "six hundred forty-five million, ninety-nine thousand".