645475600 has 240 divisors, whose sum is σ = 2037012480. Its totient is φ = 190425600.

The previous prime is 645475577. The next prime is 645475603. The reversal of 645475600 is 6574546.

It is a happy number.

It is a self number, because there is not a number n which added to its sum of digits gives 645475600.

It is not an unprimeable number, because it can be changed into a prime (645475603) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 584649 + ... + 585751.

It is an arithmetic number, because the mean of its divisors is an integer number (8487552).

Almost surely, 2^645475600 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 645475600, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1018506240).

645475600 is an abundant number, since it is smaller than the sum of its proper divisors (1391536880).

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

645475600 is a wasteful number, since it uses less digits than its factorization.

645475600 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1158 (or 1147 counting only the distinct ones).

The product of its (nonzero) digits is 100800, while the sum is 37.

The square root of 645475600 is about 25406.2118388397. The cubic root of 645475600 is about 864.2245715395.

It can be divided in two parts, 64 and 5475600, that multiplied together give a square (350438400 = 18720²).

The spelling of 645475600 in words is "six hundred forty-five million, four hundred seventy-five thousand, six hundred".