645252244 has 48 divisors (see below), whose sum is σ = 1397200896. Its totient is φ = 253900800.

The previous prime is 645252241. The next prime is 645252253. The reversal of 645252244 is 442252546.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (645252241) 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, 64884 + ... + 74164.

It is an arithmetic number, because the mean of its divisors is an integer number (29108352).

Almost surely, 2^645252244 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 645252244, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (698600448).

645252244 is an abundant number, since it is smaller than the sum of its proper divisors (751948652).

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

645252244 is a wasteful number, since it uses less digits than its factorization.

645252244 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9496 (or 9494 counting only the distinct ones).

The product of its digits is 76800, while the sum is 34.

The square root of 645252244 is about 25401.8157618703. The cubic root of 645252244 is about 864.1248765691.

The spelling of 645252244 in words is "six hundred forty-five million, two hundred fifty-two thousand, two hundred forty-four".