645135969600 has 210 divisors, whose sum is σ = 2371358021054. Its totient is φ = 172036224000.

The previous prime is 645135969559. The next prime is 645135969601. The reversal of 645135969600 is 6969531546.

645135969600 is a `hidden beast` number, since 6 + 4 + 513 + 5 + 9 + 69 + 60 + 0 = 666.

It can be written as a sum of positive squares in 3 ways, for example, as 3996262656 + 641139706944 = 63216^2 + 800712^2 .

It is a Harshad number since it is a multiple of its sum of digits (54).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (645135969601) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 29 ways as a sum of consecutive naturals, for example, 2359351 + ... + 2618550.

Almost surely, 2^645135969600 is an apocalyptic number.

645135969600 is a gapful number since it is divisible by the number (60) formed by its first and last digit.

It is an amenable number.

645135969600 is an abundant number, since it is smaller than the sum of its proper divisors (1726222051454).

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

645135969600 is a wasteful number, since it uses less digits than its factorization.

645135969600 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4977935 (or 4977911 counting only the distinct ones).

The product of its (nonzero) digits is 5248800, while the sum is 54.

The spelling of 645135969600 in words is "six hundred forty-five billion, one hundred thirty-five million, nine hundred sixty-nine thousand, six hundred".