645509088 has 336 divisors, whose sum is σ = 2247557760. Its totient is φ = 178599168.

The previous prime is 645509087. The next prime is 645509113. The reversal of 645509088 is 880905546.

645509088 is a `hidden beast` number, since 6 + 4 + 550 + 90 + 8 + 8 = 666.

It is a tau number, because it is divible by the number of its divisors (336).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (645509083) 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 55 ways as a sum of consecutive naturals, for example, 9634431 + ... + 9634497.

It is an arithmetic number, because the mean of its divisors is an integer number (6689160).

Almost surely, 2^645509088 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 645509088, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1123778880).

645509088 is an abundant number, since it is smaller than the sum of its proper divisors (1602048672).

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

645509088 is an equidigital number, since it uses as much as digits as its factorization.

645509088 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 161 (or 138 counting only the distinct ones).

The product of its (nonzero) digits is 345600, while the sum is 45.

The square root of 645509088 is about 25406.8708817123. The cubic root of 645509088 is about 864.2395169286.

The spelling of 645509088 in words is "six hundred forty-five million, five hundred nine thousand, eighty-eight".