645770400 has 288 divisors, whose sum is σ = 2336475456. Its totient is φ = 153600000.

The previous prime is 645770387. The next prime is 645770413. The reversal of 645770400 is 4077546.

645770400 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is an interprime number because it is at equal distance from previous prime (645770387) and next prime (645770413).

It is a Harshad number since it is a multiple of its sum of digits (33).

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, 1610200 + ... + 1610600.

It is an arithmetic number, because the mean of its divisors is an integer number (8112762).

Almost surely, 2^645770400 is an apocalyptic number.

645770400 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 645770400, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1168237728).

645770400 is an abundant number, since it is smaller than the sum of its proper divisors (1690705056).

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

645770400 is a wasteful number, since it uses less digits than its factorization.

645770400 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 496 (or 483 counting only the distinct ones).

The product of its (nonzero) digits is 23520, while the sum is 33.

The square root of 645770400 is about 25412.0129072846. The cubic root of 645770400 is about 864.3561203422.

The spelling of 645770400 in words is "six hundred forty-five million, seven hundred seventy thousand, four hundred".