21221011122013 has 4 divisors (see below), whose sum is σ = 21252356781660. Its totient is φ = 21189665462368.

The previous prime is 21221011121993. The next prime is 21221011122019. The reversal of 21221011122013 is 31022111012212.

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 19496445968484 + 1724565153529 = 4415478^2 + 1313227^2 .

It is a cyclic number.

It is not a de Polignac number, because 21221011122013 - 2²⁹ = 21220474251101 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21221011122019) 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, 15672828808 + ... + 15672830161.

It is an arithmetic number, because the mean of its divisors is an integer number (5313089195415).

Almost surely, 2^{21221011122013} is an apocalyptic number.

It is an amenable number.

21221011122013 is a deficient number, since it is larger than the sum of its proper divisors (31345659647).

21221011122013 is an equidigital number, since it uses as much as digits as its factorization.

21221011122013 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 31345659646.

The product of its (nonzero) digits is 96, while the sum is 19.

Adding to 21221011122013 its reverse (31022111012212), we get a palindrome (52243122134225).

The spelling of 21221011122013 in words is "twenty-one trillion, two hundred twenty-one billion, eleven million, one hundred twenty-two thousand, thirteen".