645475404 has 96 divisors (see below), whose sum is σ = 1825883136. Its totient is φ = 173479680.

The previous prime is 645475339. The next prime is 645475409. The reversal of 645475404 is 404574546.

It is not an unprimeable number, because it can be changed into a prime (645475409) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 115114 + ... + 120590.

It is an arithmetic number, because the mean of its divisors is an integer number (19019616).

Almost surely, 2^645475404 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 645475404, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (912941568).

645475404 is an abundant number, since it is smaller than the sum of its proper divisors (1180407732).

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

645475404 is a wasteful number, since it uses less digits than its factorization.

645475404 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5575 (or 5573 counting only the distinct ones).

The product of its (nonzero) digits is 268800, while the sum is 39.

The square root of 645475404 is about 25406.2079815151. The cubic root of 645475404 is about 864.2244840650.

The spelling of 645475404 in words is "six hundred forty-five million, four hundred seventy-five thousand, four hundred four".