643667120 has 40 divisors (see below), whose sum is σ = 1521070800. Its totient is φ = 253244160.

The previous prime is 643667117. The next prime is 643667147. The reversal of 643667120 is 21766346.

It is a tau number, because it is divible by the number of its divisors (40).

It is a super-2 number, since 2×643667120² = 828614722738188800, which contains 22 as substring.

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, 61070 + ... + 70829.

It is an arithmetic number, because the mean of its divisors is an integer number (38026770).

Almost surely, 2^643667120 is an apocalyptic number.

It is an amenable number.

643667120 is an abundant number, since it is smaller than the sum of its proper divisors (877403680).

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

643667120 is a wasteful number, since it uses less digits than its factorization.

643667120 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 131973 (or 131967 counting only the distinct ones).

The product of its (nonzero) digits is 36288, while the sum is 35.

The square root of 643667120 is about 25370.5955783462. The cubic root of 643667120 is about 863.4166944777.

The spelling of 643667120 in words is "six hundred forty-three million, six hundred sixty-seven thousand, one hundred twenty".