21211102120021 has 16 divisors (see below), whose sum is σ = 24501773507328. Its totient is φ = 18147611289600.

The previous prime is 21211102119997. The next prime is 21211102120037. The reversal of 21211102120021 is 12002120111212.

It is a cyclic number.

It is not a de Polignac number, because 21211102120021 - 2²¹ = 21211100022869 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 21211102119977 and 21211102120004.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21211102120321) 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, 798676 + ... + 6562018.

It is an arithmetic number, because the mean of its divisors is an integer number (1531360844208).

Almost surely, 2^{21211102120021} is an apocalyptic number.

It is an amenable number.

21211102120021 is a deficient number, since it is larger than the sum of its proper divisors (3290671387307).

21211102120021 is a wasteful number, since it uses less digits than its factorization.

21211102120021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5783052.

The product of its (nonzero) digits is 32, while the sum is 16.

Adding to 21211102120021 its reverse (12002120111212), we get a palindrome (33213222231233).

The spelling of 21211102120021 in words is "twenty-one trillion, two hundred eleven billion, one hundred two million, one hundred twenty thousand, twenty-one".