21120121110 has 64 divisors (see below), whose sum is σ = 55843893504. Its totient is φ = 5069328000.

The previous prime is 21120121091. The next prime is 21120121129. The reversal of 21120121110 is 1112102112.

It is an interprime number because it is at equal distance from previous prime (21120121091) and next prime (21120121129).

It is a Curzon number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 283504 + ... + 350163.

It is an arithmetic number, because the mean of its divisors is an integer number (872560836).

Almost surely, 2^21120121110 is an apocalyptic number.

21120121110 is an abundant number, since it is smaller than the sum of its proper divisors (34723772394).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

21120121110 is a wasteful number, since it uses less digits than its factorization.

21120121110 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 633789.

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

Adding to 21120121110 its reverse (1112102112), we get a palindrome (22232223222).

The spelling of 21120121110 in words is "twenty-one billion, one hundred twenty million, one hundred twenty-one thousand, one hundred ten".