643445712 has 120 divisors (see below), whose sum is σ = 2216358144. Its totient is φ = 169696512.

The previous prime is 643445711. The next prime is 643445729. The reversal of 643445712 is 217544346.

643445712 is a `hidden beast` number, since 6 + 43 + 44 + 571 + 2 = 666.

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 (643445711) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 11448 + ... + 37655.

Almost surely, 2^643445712 is an apocalyptic number.

It is an amenable number.

643445712 is an abundant number, since it is smaller than the sum of its proper divisors (1572912432).

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

643445712 is a wasteful number, since it uses less digits than its factorization.

643445712 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 49137 (or 49128 counting only the distinct ones).

The product of its digits is 80640, while the sum is 36.

The square root of 643445712 is about 25366.2317264508. The cubic root of 643445712 is about 863.3176840416.

The spelling of 643445712 in words is "six hundred forty-three million, four hundred forty-five thousand, seven hundred twelve".