21221121110021 has 8 divisors (see below), whose sum is σ = 24265269518784. Its totient is φ = 18180112620960.

The previous prime is 21221121110009. The next prime is 21221121110027. The reversal of 21221121110021 is 12001112112212.

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

It is a cyclic number.

It is not a de Polignac number, because 21221121110021 - 2⁶ = 21221121109957 is a prime.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21221121110027) 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, 784965440 + ... + 784992473.

It is an arithmetic number, because the mean of its divisors is an integer number (3033158689848).

Almost surely, 2^{21221121110021} is an apocalyptic number.

It is an amenable number.

21221121110021 is a deficient number, since it is larger than the sum of its proper divisors (3044148408763).

21221121110021 is a wasteful number, since it uses less digits than its factorization.

21221121110021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1569959851.

The product of its (nonzero) digits is 32, while the sum is 17.

Adding to 21221121110021 its reverse (12001112112212), we get a palindrome (33222233222233).

The spelling of 21221121110021 in words is "twenty-one trillion, two hundred twenty-one billion, one hundred twenty-one million, one hundred ten thousand, twenty-one".