164245214521 has 4 divisors (see below), whose sum is σ = 164300649552. Its totient is φ = 164189779492.

The previous prime is 164245214479. The next prime is 164245214531. The reversal of 164245214521 is 125412542461.

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, and also an emirpimes, since its reverse is a distinct semiprime: 125412542461 = 2521 ⋅49747141.

It is a cyclic number.

It is not a de Polignac number, because 164245214521 - 2²⁷ = 164110996793 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (164245214531) 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, 27713071 + ... + 27718996.

It is an arithmetic number, because the mean of its divisors is an integer number (41075162388).

Almost surely, 2^164245214521 is an apocalyptic number.

It is an amenable number.

164245214521 is a deficient number, since it is larger than the sum of its proper divisors (55435031).

164245214521 is an equidigital number, since it uses as much as digits as its factorization.

164245214521 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 55435030.

The product of its digits is 76800, while the sum is 37.

Adding to 164245214521 its reverse (125412542461), we get a palindrome (289657756982).

The spelling of 164245214521 in words is "one hundred sixty-four billion, two hundred forty-five million, two hundred fourteen thousand, five hundred twenty-one".