21220121101 has 4 divisors (see below), whose sum is σ = 22336969600. Its totient is φ = 20103272604.

The previous prime is 21220121059. The next prime is 21220121107. The reversal of 21220121101 is 10112102212.

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 a cyclic number.

It is not a de Polignac number, because 21220121101 - 2²¹ = 21218023949 is a prime.

It is a super-2 number, since 2×21220121101² (a number of 21 digits) contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21220121107) 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, 558424221 + ... + 558424258.

It is an arithmetic number, because the mean of its divisors is an integer number (5584242400).

Almost surely, 2^21220121101 is an apocalyptic number.

It is an amenable number.

21220121101 is a deficient number, since it is larger than the sum of its proper divisors (1116848499).

21220121101 is a wasteful number, since it uses less digits than its factorization.

21220121101 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1116848498.

The product of its (nonzero) digits is 16, while the sum is 13.

Adding to 21220121101 its reverse (10112102212), we get a palindrome (31332223313).

The spelling of 21220121101 in words is "twenty-one billion, two hundred twenty million, one hundred twenty-one thousand, one hundred one".