643261416 has 96 divisors (see below), whose sum is σ = 1969236000. Its totient is φ = 174109824.

The previous prime is 643261403. The next prime is 643261433. The reversal of 643261416 is 614162346.

It is a nude number because it is divisible by every one of its digits.

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, 7950 + ... + 36738.

It is an arithmetic number, because the mean of its divisors is an integer number (20512875).

Almost surely, 2^643261416 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 643261416, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (984618000).

643261416 is an abundant number, since it is smaller than the sum of its proper divisors (1325974584).

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

643261416 is a wasteful number, since it uses less digits than its factorization.

643261416 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 28831 (or 28820 counting only the distinct ones).

The product of its digits is 20736, while the sum is 33.

The square root of 643261416 is about 25362.5987627451. The cubic root of 643261416 is about 863.2352522292.

The spelling of 643261416 in words is "six hundred forty-three million, two hundred sixty-one thousand, four hundred sixteen".