643722492 has 48 divisors (see below), whose sum is σ = 1718019072. Its totient is φ = 183768000.

The previous prime is 643722491. The next prime is 643722503. The reversal of 643722492 is 294227346.

It is a happy number.

It is a self number, because there is not a number n which added to its sum of digits gives 643722492.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (643722491) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 133117 + ... + 137867.

It is an arithmetic number, because the mean of its divisors is an integer number (35792064).

Almost surely, 2^643722492 is an apocalyptic number.

It is an amenable number.

643722492 is an abundant number, since it is smaller than the sum of its proper divisors (1074296580).

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

643722492 is a wasteful number, since it uses less digits than its factorization.

643722492 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6378 (or 6376 counting only the distinct ones).

The product of its digits is 145152, while the sum is 39.

The square root of 643722492 is about 25371.6868181838. The cubic root of 643722492 is about 863.4414524812.

The spelling of 643722492 in words is "six hundred forty-three million, seven hundred twenty-two thousand, four hundred ninety-two".