645342624 has 216 divisors, whose sum is σ = 1986880896. Its totient is φ = 198374400.

The previous prime is 645342623. The next prime is 645342637. The reversal of 645342624 is 426243546.

645342624 is a `hidden beast` number, since 64 + 534 + 2 + 62 + 4 = 666.

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

Its product of digits (138240) is a multiple of the sum of its prime divisors (120).

It is not an unprimeable number, because it can be changed into a prime (645342623) 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, 15007947 + ... + 15007989.

Almost surely, 2^645342624 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 645342624, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (993440448).

645342624 is an abundant number, since it is smaller than the sum of its proper divisors (1341538272).

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

645342624 is a wasteful number, since it uses less digits than its factorization.

645342624 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 172 (or 120 counting only the distinct ones).

The product of its digits is 138240, while the sum is 36.

The square root of 645342624 is about 25403.5947062616. The cubic root of 645342624 is about 864.1652204609.

The spelling of 645342624 in words is "six hundred forty-five million, three hundred forty-two thousand, six hundred twenty-four".