21121001211121 has 8 divisors (see below), whose sum is σ = 24151356028800. Its totient is φ = 18093913626048.

The previous prime is 21121001211113. The next prime is 21121001211151. The reversal of 21121001211121 is 12111210012112.

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 21121001211121 - 2³ = 21121001211113 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 21121001211095 and 21121001211104.

It is not an unprimeable number, because it can be changed into a prime (21121001211151) 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, 816794296 + ... + 816820153.

It is an arithmetic number, because the mean of its divisors is an integer number (3018919503600).

Almost surely, 2^{21121001211121} is an apocalyptic number.

It is an amenable number.

21121001211121 is a deficient number, since it is larger than the sum of its proper divisors (3030354817679).

21121001211121 is a wasteful number, since it uses less digits than its factorization.

21121001211121 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1633616303.

The product of its (nonzero) digits is 16, while the sum is 16.

Adding to 21121001211121 its reverse (12111210012112), we get a palindrome (33232211223233).

The spelling of 21121001211121 in words is "twenty-one trillion, one hundred twenty-one billion, one million, two hundred eleven thousand, one hundred twenty-one".