164165642221 has 24 divisors (see below), whose sum is σ = 201241819680. Its totient is φ = 133159777632.

The previous prime is 164165642189. The next prime is 164165642233. The reversal of 164165642221 is 122246561461.

It is not a de Polignac number, because 164165642221 - 2⁵ = 164165642189 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (164165642521) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 747211 + ... + 941623.

It is an arithmetic number, because the mean of its divisors is an integer number (8385075820).

Almost surely, 2^164165642221 is an apocalyptic number.

It is an amenable number.

164165642221 is a deficient number, since it is larger than the sum of its proper divisors (37076177459).

164165642221 is a wasteful number, since it uses less digits than its factorization.

164165642221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 195353 (or 195346 counting only the distinct ones).

The product of its digits is 138240, while the sum is 40.

The spelling of 164165642221 in words is "one hundred sixty-four billion, one hundred sixty-five million, six hundred forty-two thousand, two hundred twenty-one".