645465600 has 360 divisors, whose sum is σ = 2493402912. Its totient is φ = 158515200.

The previous prime is 645465599. The next prime is 645465607. The reversal of 645465600 is 6564546.

It is a happy number.

645465600 is a `hidden beast` number, since 6 + 4 + 5 + 46 + 5 + 600 = 666.

It is a tau number, because it is divible by the number of its divisors (360).

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 (645465607) by changing a digit.

It is a polite number, since it can be written in 35 ways as a sum of consecutive naturals, for example, 1497385 + ... + 1497815.

Almost surely, 2^645465600 is an apocalyptic number.

645465600 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 645465600, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1246701456).

645465600 is an abundant number, since it is smaller than the sum of its proper divisors (1847937312).

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

645465600 is a wasteful number, since it uses less digits than its factorization.

645465600 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 478 (or 454 counting only the distinct ones).

The product of its (nonzero) digits is 86400, while the sum is 36.

The square root of 645465600 is about 25406.0150358139. The cubic root of 645465600 is about 864.2201085305.

The spelling of 645465600 in words is "six hundred forty-five million, four hundred sixty-five thousand, six hundred".