21365025205201 has 4 divisors (see below), whose sum is σ = 21768138888372. Its totient is φ = 20961911522032.

The previous prime is 21365025205189. The next prime is 21365025205241. The reversal of 21365025205201 is 10250252056312.

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

It can be written as a sum of positive squares in 2 ways, for example, as 15654841824400 + 5710183380801 = 3956620^2 + 2389599^2 .

It is a cyclic number.

It is not a de Polignac number, because 21365025205201 - 2³⁵ = 21330665466833 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21365025205241) 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, 201556841506 + ... + 201556841611.

It is an arithmetic number, because the mean of its divisors is an integer number (5442034722093).

Almost surely, 2^{21365025205201} is an apocalyptic number.

It is an amenable number.

21365025205201 is a deficient number, since it is larger than the sum of its proper divisors (403113683171).

21365025205201 is an equidigital number, since it uses as much as digits as its factorization.

21365025205201 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 403113683170.

The product of its (nonzero) digits is 36000, while the sum is 34.

The spelling of 21365025205201 in words is "twenty-one trillion, three hundred sixty-five billion, twenty-five million, two hundred five thousand, two hundred one".