221000013121 has 4 divisors (see below), whose sum is σ = 221492218500. Its totient is φ = 220507807744.

The previous prime is 221000013077. The next prime is 221000013137. The reversal of 221000013121 is 121310000122.

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 98163782721 + 122836230400 = 313311^2 + 350480^2 .

It is a cyclic number.

It is not a de Polignac number, because 221000013121 - 2¹⁷ = 220999882049 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (221000013151) 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, 246102016 + ... + 246102913.

It is an arithmetic number, because the mean of its divisors is an integer number (55373054625).

Almost surely, 2^221000013121 is an apocalyptic number.

It is an amenable number.

221000013121 is a deficient number, since it is larger than the sum of its proper divisors (492205379).

221000013121 is an equidigital number, since it uses as much as digits as its factorization.

221000013121 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 492205378.

The product of its (nonzero) digits is 24, while the sum is 13.

Adding to 221000013121 its reverse (121310000122), we get a palindrome (342310013243).

The spelling of 221000013121 in words is "two hundred twenty-one billion, thirteen thousand, one hundred twenty-one".