21121001122121 has 8 divisors (see below), whose sum is σ = 22363453340064. Its totient is φ = 19878553391680.

The previous prime is 21121001122097. The next prime is 21121001122127. The reversal of 21121001122121 is 12122110012112.

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 21121001122121 - 2¹⁰ = 21121001121097 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (17).

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 21121001122121.

It is not an unprimeable number, because it can be changed into a prime (21121001122127) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 16285226 + ... + 17534268.

It is an arithmetic number, because the mean of its divisors is an integer number (2795431667508).

Almost surely, 2^{21121001122121} is an apocalyptic number.

It is an amenable number.

21121001122121 is a deficient number, since it is larger than the sum of its proper divisors (1242452217943).

21121001122121 is a wasteful number, since it uses less digits than its factorization.

21121001122121 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2243751.

The product of its (nonzero) digits is 32, while the sum is 17.

Adding to 21121001122121 its reverse (12122110012112), we get a palindrome (33243111134233).

The spelling of 21121001122121 in words is "twenty-one trillion, one hundred twenty-one billion, one million, one hundred twenty-two thousand, one hundred twenty-one".