645067800 has 288 divisors, whose sum is σ = 2421772080. Its totient is φ = 158630400.

The previous prime is 645067799. The next prime is 645067807. The reversal of 645067800 is 8760546.

It is a happy number.

645067800 is a `hidden beast` number, since 645 + 0 + 6 + 7 + 8 + 0 + 0 = 666.

It is a super-2 number, since 2×645067800² = 832224933193680000, which contains 22 as substring.

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

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (645067807) by changing a digit.

It is a polite number, since it can be written in 71 ways as a sum of consecutive naturals, for example, 631290 + ... + 632310.

Almost surely, 2^645067800 is an apocalyptic number.

645067800 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 645067800, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1210886040).

645067800 is an abundant number, since it is smaller than the sum of its proper divisors (1776704280).

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

645067800 is a wasteful number, since it uses less digits than its factorization.

645067800 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1065 (or 1044 counting only the distinct ones).

The product of its (nonzero) digits is 40320, while the sum is 36.

The square root of 645067800 is about 25398.1849745213. The cubic root of 645067800 is about 864.0425326284.

The spelling of 645067800 in words is "six hundred forty-five million, sixty-seven thousand, eight hundred".