21111121010221 has 8 divisors (see below), whose sum is σ = 23030834619744. Its totient is φ = 19191494199120.

The previous prime is 21111121010149. The next prime is 21111121010227. The reversal of 21111121010221 is 12201012111112.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21111121010221 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 21111121010195 and 21111121010204.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21111121010227) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 21190530 + ... + 22164403.

It is an arithmetic number, because the mean of its divisors is an integer number (2878854327468).

Almost surely, 2^{21111121010221} is an apocalyptic number.

It is an amenable number.

21111121010221 is a deficient number, since it is larger than the sum of its proper divisors (1919713609523).

21111121010221 is a wasteful number, since it uses less digits than its factorization.

21111121010221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 43399211.

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

Adding to 21111121010221 its reverse (12201012111112), we get a palindrome (33312133121333).

The spelling of 21111121010221 in words is "twenty-one trillion, one hundred eleven billion, one hundred twenty-one million, ten thousand, two hundred twenty-one".