164373565021 has 12 divisors (see below), whose sum is σ = 170176118940. Its totient is φ = 158746822080.

The previous prime is 164373565001. The next prime is 164373565087. The reversal of 164373565021 is 120565373461.

It can be written as a sum of positive squares in 2 ways, for example, as 103729084900 + 60644480121 = 322070^2 + 246261^2 .

It is not a de Polignac number, because 164373565021 - 2⁵ = 164373564989 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (43).

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (164373565001) 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, 334870 + ... + 663991.

It is an arithmetic number, because the mean of its divisors is an integer number (14181343245).

Almost surely, 2^164373565021 is an apocalyptic number.

It is an amenable number.

164373565021 is a deficient number, since it is larger than the sum of its proper divisors (5802553919).

164373565021 is an frugal number, since it uses more digits than its factorization.

164373565021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 999036 (or 998993 counting only the distinct ones).

The product of its (nonzero) digits is 453600, while the sum is 43.

The spelling of 164373565021 in words is "one hundred sixty-four billion, three hundred seventy-three million, five hundred sixty-five thousand, twenty-one".