643655152 has 40 divisors (see below), whose sum is σ = 1432448000. Its totient is φ = 274456512.

The previous prime is 643655149. The next prime is 643655171. The reversal of 643655152 is 251556346.

It is a super-2 number, since 2×643655152² = 828583909392286208, which contains 22 as substring.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 7849 + ... + 36727.

It is an arithmetic number, because the mean of its divisors is an integer number (35811200).

Almost surely, 2^643655152 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 643655152, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (716224000).

643655152 is an abundant number, since it is smaller than the sum of its proper divisors (788792848).

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

643655152 is a wasteful number, since it uses less digits than its factorization.

643655152 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 29093 (or 29087 counting only the distinct ones).

The product of its digits is 108000, while the sum is 37.

The square root of 643655152 is about 25370.3597136501. The cubic root of 643655152 is about 863.4113431428.

The spelling of 643655152 in words is "six hundred forty-three million, six hundred fifty-five thousand, one hundred fifty-two".