21164212026571 has 4 divisors (see below), whose sum is σ = 21680412319944. Its totient is φ = 20648011733200.

The previous prime is 21164212026541. The next prime is 21164212026647. The reversal of 21164212026571 is 17562021246112.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 21164212026571 - 2¹³ = 21164212018379 is a prime.

It is a Smith number, since the sum of its digits (40) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21164212026541) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (29) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 258100146625 + ... + 258100146706.

It is an arithmetic number, because the mean of its divisors is an integer number (5420103079986).

Almost surely, 2^{21164212026571} is an apocalyptic number.

21164212026571 is a deficient number, since it is larger than the sum of its proper divisors (516200293373).

21164212026571 is an equidigital number, since it uses as much as digits as its factorization.

21164212026571 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 516200293372.

The product of its (nonzero) digits is 80640, while the sum is 40.

The spelling of 21164212026571 in words is "twenty-one trillion, one hundred sixty-four billion, two hundred twelve million, twenty-six thousand, five hundred seventy-one".