21121222211121 has 8 divisors (see below), whose sum is σ = 28235934707680. Its totient is φ = 14043662260992.

The previous prime is 21121222211107. The next prime is 21121222211143. The reversal of 21121222211121 is 12111222212112.

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

It is not a de Polignac number, because 21121222211121 - 2⁶ = 21121222211057 is a prime.

It is a super-2 number, since 2×21121222211121² (a number of 27 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21121222211521) 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, 9288135280 + ... + 9288137553.

It is an arithmetic number, because the mean of its divisors is an integer number (3529491838460).

Almost surely, 2^{21121222211121} is an apocalyptic number.

It is an amenable number.

21121222211121 is a deficient number, since it is larger than the sum of its proper divisors (7114712496559).

21121222211121 is a wasteful number, since it uses less digits than its factorization.

21121222211121 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 18576273215.

The product of its digits is 128, while the sum is 21.

Adding to 21121222211121 its reverse (12111222212112), we get a palindrome (33232444423233).

Subtracting from 21121222211121 its reverse (12111222212112), we obtain a palindrome (9009999999009).

The spelling of 21121222211121 in words is "twenty-one trillion, one hundred twenty-one billion, two hundred twenty-two million, two hundred eleven thousand, one hundred twenty-one".