643652064 has 72 divisors (see below), whose sum is σ = 1996794072. Its totient is φ = 195045120.

The previous prime is 643652059. The next prime is 643652069. The reversal of 643652064 is 460256346.

643652064 is a `hidden beast` number, since 643 + 6 + 5 + 2 + 0 + 6 + 4 = 666.

643652064 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is an interprime number because it is at equal distance from previous prime (643652059) and next prime (643652069).

It is a tau number, because it is divible by the number of its divisors (72).

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

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (643652069) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 98419 + ... + 104754.

It is an arithmetic number, because the mean of its divisors is an integer number (27733251).

Almost surely, 2^643652064 is an apocalyptic number.

It is an amenable number.

643652064 is an abundant number, since it is smaller than the sum of its proper divisors (1353142008).

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

643652064 is a wasteful number, since it uses less digits than its factorization.

643652064 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 203200 (or 203189 counting only the distinct ones).

The product of its (nonzero) digits is 103680, while the sum is 36.

The square root of 643652064 is about 25370.2988551574. The cubic root of 643652064 is about 863.4099623732.

The spelling of 643652064 in words is "six hundred forty-three million, six hundred fifty-two thousand, sixty-four".