21366545520371 has 4 divisors (see below), whose sum is σ = 21395458302600. Its totient is φ = 21337632738144.

The previous prime is 21366545520329. The next prime is 21366545520409. The reversal of 21366545520371 is 17302554566312.

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 21366545520371 - 2¹⁴ = 21366545503987 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21366545520071) 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, 14456390006 + ... + 14456391483.

It is an arithmetic number, because the mean of its divisors is an integer number (5348864575650).

Almost surely, 2^{21366545520371} is an apocalyptic number.

21366545520371 is a deficient number, since it is larger than the sum of its proper divisors (28912782229).

21366545520371 is an equidigital number, since it uses as much as digits as its factorization.

21366545520371 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 28912782228.

The product of its (nonzero) digits is 4536000, while the sum is 50.

The spelling of 21366545520371 in words is "twenty-one trillion, three hundred sixty-six billion, five hundred forty-five million, five hundred twenty thousand, three hundred seventy-one".