643221464 has 32 divisors (see below), whose sum is σ = 1220929200. Its totient is φ = 317665920.

The previous prime is 643221463. The next prime is 643221517. The reversal of 643221464 is 464122346.

It is a self number, because there is not a number n which added to its sum of digits gives 643221464.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (643221463) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 223394 + ... + 226254.

Almost surely, 2^643221464 is an apocalyptic number.

It is an amenable number.

643221464 is a deficient number, since it is larger than the sum of its proper divisors (577707736).

643221464 is a wasteful number, since it uses less digits than its factorization.

643221464 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3203 (or 3199 counting only the distinct ones).

The product of its digits is 27648, while the sum is 32.

The square root of 643221464 is about 25361.8111340653. The cubic root of 643221464 is about 863.2173804443.

The spelling of 643221464 in words is "six hundred forty-three million, two hundred twenty-one thousand, four hundred sixty-four".