643622760 has 160 divisors (see below), whose sum is σ = 2360080800. Its totient is φ = 156021120.

The previous prime is 643622711. The next prime is 643622761. The reversal of 643622760 is 67226346.

It is a happy number.

643622760 is a `hidden beast` number, since 643 + 6 + 2 + 2 + 7 + 6 + 0 = 666.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is not an unprimeable number, because it can be changed into a prime (643622761) by changing a digit.

It is a polite number, since it can be written in 39 ways as a sum of consecutive naturals, for example, 26611 + ... + 44669.

It is an arithmetic number, because the mean of its divisors is an integer number (14750505).

Almost surely, 2^643622760 is an apocalyptic number.

643622760 is a gapful number since it is divisible by the number (60) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 643622760, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1180040400).

643622760 is an abundant number, since it is smaller than the sum of its proper divisors (1716458040).

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

643622760 is a wasteful number, since it uses less digits than its factorization.

643622760 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 18093 (or 18080 counting only the distinct ones).

The product of its (nonzero) digits is 72576, while the sum is 36.

The square root of 643622760 is about 25369.7213228683. The cubic root of 643622760 is about 863.3968591502.

The spelling of 643622760 in words is "six hundred forty-three million, six hundred twenty-two thousand, seven hundred sixty".