645412320 has 288 divisors, whose sum is σ = 2628612000. Its totient is φ = 147474432.

The previous prime is 645412309. The next prime is 645412363. The reversal of 645412320 is 23214546.

645412320 is a `hidden beast` number, since 645 + 4 + 12 + 3 + 2 + 0 = 666.

It is a tau number, because it is divible by the number of its divisors (288).

It is a Harshad number since it is a multiple of its sum of digits (27).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 210156 + ... + 213204.

It is an arithmetic number, because the mean of its divisors is an integer number (9127125).

Almost surely, 2^645412320 is an apocalyptic number.

645412320 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 645412320, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1314306000).

645412320 is an abundant number, since it is smaller than the sum of its proper divisors (1983199680).

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

645412320 is a wasteful number, since it uses less digits than its factorization.

645412320 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3087 (or 3066 counting only the distinct ones).

The product of its (nonzero) digits is 5760, while the sum is 27.

The square root of 645412320 is about 25404.9664435913. The cubic root of 645412320 is about 864.1963288411.

Adding to 645412320 its reverse (23214546), we get a palindrome (668626866).

The spelling of 645412320 in words is "six hundred forty-five million, four hundred twelve thousand, three hundred twenty".