21220101111021 has 16 divisors (see below), whose sum is σ = 28519724279808. Its totient is φ = 14033633140800.

The previous prime is 21220101110983. The next prime is 21220101111031. The reversal of 21220101111021 is 12011110102212.

It is a happy number.

It is not a de Polignac number, because 21220101111021 - 2⁷ = 21220101110893 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21220101111031) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 255210 + ... + 6519611.

It is an arithmetic number, because the mean of its divisors is an integer number (1782482767488).

Almost surely, 2^{21220101111021} is an apocalyptic number.

It is an amenable number.

21220101111021 is a deficient number, since it is larger than the sum of its proper divisors (7299623168787).

21220101111021 is a wasteful number, since it uses less digits than its factorization.

21220101111021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6783172.

The product of its (nonzero) digits is 16, while the sum is 15.

Adding to 21220101111021 its reverse (12011110102212), we get a palindrome (33231211213233).

The spelling of 21220101111021 in words is "twenty-one trillion, two hundred twenty billion, one hundred one million, one hundred eleven thousand, twenty-one".