21021110121 has 32 divisors (see below), whose sum is σ = 31023336960. Its totient is φ = 12554528000.

The previous prime is 21021110119. The next prime is 21021110129. The reversal of 21021110121 is 12101112012.

It is a cyclic number.

It is not a de Polignac number, because 21021110121 - 2¹ = 21021110119 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 21021110097 and 21021110106.

It is not an unprimeable number, because it can be changed into a prime (21021110129) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 1088770 + ... + 1107908.

It is an arithmetic number, because the mean of its divisors is an integer number (969479280).

Almost surely, 2^21021110121 is an apocalyptic number.

It is an amenable number.

21021110121 is a deficient number, since it is larger than the sum of its proper divisors (10002226839).

21021110121 is a wasteful number, since it uses less digits than its factorization.

21021110121 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 19637.

The product of its (nonzero) digits is 8, while the sum is 12.

Adding to 21021110121 its reverse (12101112012), we get a palindrome (33122222133).

The spelling of 21021110121 in words is "twenty-one billion, twenty-one million, one hundred ten thousand, one hundred twenty-one".