643606524 has 72 divisors (see below), whose sum is σ = 1781375232. Its totient is φ = 194309280.

The previous prime is 643606487. The next prime is 643606559. The reversal of 643606524 is 425606346.

643606524 is a `hidden beast` number, since 6 + 43 + 606 + 5 + 2 + 4 = 666.

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

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 109197 + ... + 114939.

Almost surely, 2^643606524 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 643606524, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (890687616).

643606524 is an abundant number, since it is smaller than the sum of its proper divisors (1137768708).

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

643606524 is a wasteful number, since it uses less digits than its factorization.

643606524 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6047 (or 6042 counting only the distinct ones).

The product of its (nonzero) digits is 103680, while the sum is 36.

The square root of 643606524 is about 25369.4013331020. The cubic root of 643606524 is about 863.3895990852.

The spelling of 643606524 in words is "six hundred forty-three million, six hundred six thousand, five hundred twenty-four".