645241604 has 18 divisors (see below), whose sum is σ = 1313527950. Its totient is φ = 276532032.

The previous prime is 645241603. The next prime is 645241633. The reversal of 645241604 is 406142546.

It can be written as a sum of positive squares in only one way, i.e., 353515204 + 291726400 = 18802^2 + 17080^2 .

It is a super-3 number, since 3×645241604³ (a number of 27 digits) contains 333 as substring.

It is not an unprimeable number, because it can be changed into a prime (645241601) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 1645829 + ... + 1646220.

It is an arithmetic number, because the mean of its divisors is an integer number (72973775).

Almost surely, 2^645241604 is an apocalyptic number.

It is an amenable number.

645241604 is an abundant number, since it is smaller than the sum of its proper divisors (668286346).

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

645241604 is a wasteful number, since it uses less digits than its factorization.

645241604 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3292067 (or 3292058 counting only the distinct ones).

The product of its (nonzero) digits is 23040, while the sum is 32.

The square root of 645241604 is about 25401.6063271597. The cubic root of 645241604 is about 864.1201268301.

The spelling of 645241604 in words is "six hundred forty-five million, two hundred forty-one thousand, six hundred four".