21201120121 has 8 divisors (see below), whose sum is σ = 22828724640. Its totient is φ = 19615791168.

The previous prime is 21201120097. The next prime is 21201120133. The reversal of 21201120121 is 12102110212.

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 21201120121 - 2⁷ = 21201119993 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21201120221) 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, 10567851 + ... + 10569856.

It is an arithmetic number, because the mean of its divisors is an integer number (2853590580).

Almost surely, 2^21201120121 is an apocalyptic number.

It is an amenable number.

21201120121 is a deficient number, since it is larger than the sum of its proper divisors (1627604519).

21201120121 is a wasteful number, since it uses less digits than its factorization.

21201120121 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 21137783.

The product of its (nonzero) digits is 16, while the sum is 13.

Adding to 21201120121 its reverse (12102110212), we get a palindrome (33303230333).

Subtracting from 21201120121 its reverse (12102110212), we obtain a palindrome (9099009909).

The spelling of 21201120121 in words is "twenty-one billion, two hundred one million, one hundred twenty thousand, one hundred twenty-one".