643669292 has 36 divisors (see below), whose sum is σ = 1319946264. Its totient is φ = 273833280.

The previous prime is 643669261. The next prime is 643669309. The reversal of 643669292 is 292966346.

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 14867 + ... + 38837.

It is an arithmetic number, because the mean of its divisors is an integer number (36665174).

Almost surely, 2^643669292 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 643669292, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (659973132).

643669292 is an abundant number, since it is smaller than the sum of its proper divisors (676276972).

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

643669292 is a wasteful number, since it uses less digits than its factorization.

643669292 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 24126 (or 24117 counting only the distinct ones).

The product of its digits is 839808, while the sum is 47.

The square root of 643669292 is about 25370.6383837695. The cubic root of 643669292 is about 863.4176656521.

The spelling of 643669292 in words is "six hundred forty-three million, six hundred sixty-nine thousand, two hundred ninety-two".