21012212011121 has 16 divisors (see below), whose sum is σ = 21607854710400. Its totient is φ = 20420550940800.

The previous prime is 21012212011117. The next prime is 21012212011123. The reversal of 21012212011121 is 12111021221012.

It is a cyclic number.

It is not a de Polignac number, because 21012212011121 - 2² = 21012212011117 is a prime.

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 21012212011121.

It is not an unprimeable number, because it can be changed into a prime (21012212011123) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 77939726 + ... + 78208856.

It is an arithmetic number, because the mean of its divisors is an integer number (1350490919400).

Almost surely, 2^{21012212011121} is an apocalyptic number.

It is an amenable number.

21012212011121 is a deficient number, since it is larger than the sum of its proper divisors (595642699279).

21012212011121 is a wasteful number, since it uses less digits than its factorization.

21012212011121 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 276520.

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

Adding to 21012212011121 its reverse (12111021221012), we get a palindrome (33123233232133).

The spelling of 21012212011121 in words is "twenty-one trillion, twelve billion, two hundred twelve million, eleven thousand, one hundred twenty-one".