645475500 has 192 divisors, whose sum is σ = 2109744000. Its totient is φ = 170380800.

The previous prime is 645475489. The next prime is 645475531. The reversal of 645475500 is 5574546.

It is a happy number.

645475500 is a `hidden beast` number, since 64 + 5 + 47 + 550 + 0 = 666.

645475500 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a super-2 number, since 2×645475500² = 833277242200500000, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is an unprimeable number.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 1849326 + ... + 1849674.

It is an arithmetic number, because the mean of its divisors is an integer number (10988250).

Almost surely, 2^645475500 is an apocalyptic number.

645475500 is a gapful number since it is divisible by the number (60) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 645475500, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1054872000).

645475500 is an abundant number, since it is smaller than the sum of its proper divisors (1464268500).

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

645475500 is a wasteful number, since it uses less digits than its factorization.

645475500 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 514 (or 496 counting only the distinct ones).

The product of its (nonzero) digits is 84000, while the sum is 36.

The square root of 645475500 is about 25406.2098708170. The cubic root of 645475500 is about 864.2245269097.

The spelling of 645475500 in words is "six hundred forty-five million, four hundred seventy-five thousand, five hundred".