643625464 has 8 divisors (see below), whose sum is σ = 1206797760. Its totient is φ = 321812728.

The previous prime is 643625443. The next prime is 643625509. The reversal of 643625464 is 464526346.

It is a tau number, because it is divible by the number of its divisors (8).

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 40226584 + ... + 40226599.

It is an arithmetic number, because the mean of its divisors is an integer number (150849720).

Almost surely, 2^643625464 is an apocalyptic number.

It is an amenable number.

643625464 is a deficient number, since it is larger than the sum of its proper divisors (563172296).

643625464 is a wasteful number, since it uses less digits than its factorization.

643625464 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 80453189 (or 80453185 counting only the distinct ones).

The product of its digits is 414720, while the sum is 40.

The square root of 643625464 is about 25369.7746146867. The cubic root of 643625464 is about 863.3980682549.

The spelling of 643625464 in words is "six hundred forty-three million, six hundred twenty-five thousand, four hundred sixty-four".