21110021121 has 8 divisors (see below), whose sum is σ = 32167651264. Its totient is φ = 12062869200.

The previous prime is 21110021063. The next prime is 21110021123. The reversal of 21110021121 is 12112001112.

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

It is not a de Polignac number, because 21110021121 - 2⁶ = 21110021057 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 21110021097 and 21110021106.

It is not an unprimeable number, because it can be changed into a prime (21110021123) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 502619530 + ... + 502619571.

It is an arithmetic number, because the mean of its divisors is an integer number (4020956408).

Almost surely, 2^21110021121 is an apocalyptic number.

21110021121 is a gapful number since it is divisible by the number (21) formed by its first and last digit.

It is an amenable number.

21110021121 is a deficient number, since it is larger than the sum of its proper divisors (11057630143).

21110021121 is a wasteful number, since it uses less digits than its factorization.

21110021121 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1005239111.

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

Adding to 21110021121 its reverse (12112001112), we get a palindrome (33222022233).

It can be divided in two parts, 211100 and 21121, that added together give a triangular number (232221 = T₆₈₁).

The spelling of 21110021121 in words is "twenty-one billion, one hundred ten million, twenty-one thousand, one hundred twenty-one".