21020122121 has 8 divisors (see below), whose sum is σ = 21231197184. Its totient is φ = 20809105200.

The previous prime is 21020122093. The next prime is 21020122129. The reversal of 21020122121 is 12122102012.

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 21020122121 - 2¹⁸ = 21019859977 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 21020122096 and 21020122105.

It is not an unprimeable number, because it can be changed into a prime (21020122129) 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, 1323590 + ... + 1339376.

It is an arithmetic number, because the mean of its divisors is an integer number (2653899648).

Almost surely, 2^21020122121 is an apocalyptic number.

It is an amenable number.

21020122121 is a deficient number, since it is larger than the sum of its proper divisors (211075063).

21020122121 is a wasteful number, since it uses less digits than its factorization.

21020122121 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 29071.

The product of its (nonzero) digits is 32, while the sum is 14.

Adding to 21020122121 its reverse (12122102012), we get a palindrome (33142224133).

The spelling of 21020122121 in words is "twenty-one billion, twenty million, one hundred twenty-two thousand, one hundred twenty-one".