643166061 has 4 divisors (see below), whose sum is σ = 857554752. Its totient is φ = 428777372.

The previous prime is 643166053. The next prime is 643166063. The reversal of 643166061 is 160661346.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 643166061 - 2³ = 643166053 is a prime.

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 (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 107194341 + ... + 107194346.

It is an arithmetic number, because the mean of its divisors is an integer number (214388688).

Almost surely, 2^643166061 is an apocalyptic number.

It is an amenable number.

643166061 is a deficient number, since it is larger than the sum of its proper divisors (214388691).

643166061 is a wasteful number, since it uses less digits than its factorization.

643166061 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 214388690.

The product of its (nonzero) digits is 15552, while the sum is 33.

The square root of 643166061 is about 25360.7188581081. The cubic root of 643166061 is about 863.1925957171.

The spelling of 643166061 in words is "six hundred forty-three million, one hundred sixty-six thousand, sixty-one".