643166064 has 60 divisors (see below), whose sum is σ = 1801677592. Its totient is φ = 214185600.

The previous prime is 643166063. The next prime is 643166101. The reversal of 643166064 is 460661346.

643166064 is a `hidden beast` number, since 6 + 43 + 1 + 6 + 606 + 4 = 666.

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 (643166063) by changing a digit.

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 in 11 ways as a sum of consecutive naturals, for example, 288474 + ... + 290694.

Almost surely, 2^643166064 is an apocalyptic number.

It is an amenable number.

643166064 is an abundant number, since it is smaller than the sum of its proper divisors (1158511528).

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

643166064 is a wasteful number, since it uses less digits than its factorization.

643166064 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4246 (or 4237 counting only the distinct ones).

The product of its (nonzero) digits is 62208, while the sum is 36.

The square root of 643166064 is about 25360.7189172547. The cubic root of 643166064 is about 863.1925970592.

The spelling of 643166064 in words is "six hundred forty-three million, one hundred sixty-six thousand, sixty-four".