643820466 has 16 divisors (see below), whose sum is σ = 1292654304. Its totient is φ = 213771264.

The previous prime is 643820407. The next prime is 643820477. The reversal of 643820466 is 664028346.

It is a Curzon number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 207220 + ... + 210303.

It is an arithmetic number, because the mean of its divisors is an integer number (80790894).

Almost surely, 2^643820466 is an apocalyptic number.

643820466 is an abundant number, since it is smaller than the sum of its proper divisors (648833838).

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

643820466 is a wasteful number, since it uses less digits than its factorization.

643820466 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 417785.

The product of its (nonzero) digits is 165888, while the sum is 39.

The square root of 643820466 is about 25373.6175189901. The cubic root of 643820466 is about 863.4852552702.

The spelling of 643820466 in words is "six hundred forty-three million, eight hundred twenty thousand, four hundred sixty-six".