645990250 has 32 divisors (see below), whose sum is σ = 1221083136. Its totient is φ = 255877200.

The previous prime is 645990227. The next prime is 645990251. The reversal of 645990250 is 52099546.

It is not an unprimeable number, because it can be changed into a prime (645990251) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 13207 + ... + 38293.

It is an arithmetic number, because the mean of its divisors is an integer number (38158848).

Almost surely, 2^645990250 is an apocalyptic number.

645990250 is a deficient number, since it is larger than the sum of its proper divisors (575092886).

645990250 is a wasteful number, since it uses less digits than its factorization.

645990250 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 25207 (or 25197 counting only the distinct ones).

The product of its (nonzero) digits is 97200, while the sum is 40.

The square root of 645990250 is about 25416.3382492443. The cubic root of 645990250 is about 864.4541980968.

The spelling of 645990250 in words is "six hundred forty-five million, nine hundred ninety thousand, two hundred fifty".