164644073178681 has 4 divisors (see below), whose sum is σ = 219525430904912. Its totient is φ = 109762715452452.

The previous prime is 164644073178653. The next prime is 164644073178719. The reversal of 164644073178681 is 186871370446461.

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 not a de Polignac number, because 164644073178681 - 2¹⁷ = 164644073047609 is a prime.

It is a super-2 number, since 2×164644073178681² (a number of 29 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (164644073178881) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 27440678863111 + ... + 27440678863116.

It is an arithmetic number, because the mean of its divisors is an integer number (54881357726228).

Almost surely, 2^{164644073178681} is an apocalyptic number.

It is an amenable number.

164644073178681 is a deficient number, since it is larger than the sum of its proper divisors (54881357726231).

164644073178681 is an equidigital number, since it uses as much as digits as its factorization.

164644073178681 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 54881357726230.

The product of its (nonzero) digits is 130056192, while the sum is 66.

The spelling of 164644073178681 in words is "one hundred sixty-four trillion, six hundred forty-four billion, seventy-three million, one hundred seventy-eight thousand, six hundred eighty-one".