21220010121 has 4 divisors (see below), whose sum is σ = 28293346832. Its totient is φ = 14146673412.

The previous prime is 21220010107. The next prime is 21220010137. The reversal of 21220010121 is 12101002212.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is not a de Polignac number, because 21220010121 - 2⁵ = 21220010089 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 21220010097 and 21220010106.

It is not an unprimeable number, because it can be changed into a prime (21220010171) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 3536668351 + ... + 3536668356.

It is an arithmetic number, because the mean of its divisors is an integer number (7073336708).

Almost surely, 2^21220010121 is an apocalyptic number.

It is an amenable number.

21220010121 is a deficient number, since it is larger than the sum of its proper divisors (7073336711).

21220010121 is an equidigital number, since it uses as much as digits as its factorization.

21220010121 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7073336710.

The product of its (nonzero) digits is 16, while the sum is 12.

Adding to 21220010121 its reverse (12101002212), we get a palindrome (33321012333).

The spelling of 21220010121 in words is "twenty-one billion, two hundred twenty million, ten thousand, one hundred twenty-one".