21220101110021 has 4 divisors (see below), whose sum is σ = 23149201210944. Its totient is φ = 19291001009100.

The previous prime is 21220101110011. The next prime is 21220101110053. The reversal of 21220101110021 is 12001110102212.

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 21220101110021 - 2⁶ = 21220101109957 is a prime.

It is a super-2 number, since 2×21220101110021² (a number of 27 digits) contains 22 as substring.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 21220101109978 and 21220101110005.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21220101110011) 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, 964550050445 + ... + 964550050466.

It is an arithmetic number, because the mean of its divisors is an integer number (5787300302736).

Almost surely, 2^{21220101110021} is an apocalyptic number.

It is an amenable number.

21220101110021 is a deficient number, since it is larger than the sum of its proper divisors (1929100100923).

21220101110021 is a wasteful number, since it uses less digits than its factorization.

21220101110021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1929100100922.

The product of its (nonzero) digits is 16, while the sum is 14.

Adding to 21220101110021 its reverse (12001110102212), we get a palindrome (33221211212233).

The spelling of 21220101110021 in words is "twenty-one trillion, two hundred twenty billion, one hundred one million, one hundred ten thousand, twenty-one".