21212122222091 has 8 divisors (see below), whose sum is σ = 21481136702400. Its totient is φ = 20943120407040.

The previous prime is 21212122222073. The next prime is 21212122222103. The reversal of 21212122222091 is 19022222121212.

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 21212122222091 - 2²² = 21212118027787 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21212122222001) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 227501 + ... + 6517361.

It is an arithmetic number, because the mean of its divisors is an integer number (2685142087800).

Almost surely, 2^{21212122222091} is an apocalyptic number.

21212122222091 is a deficient number, since it is larger than the sum of its proper divisors (269014480309).

21212122222091 is an equidigital number, since it uses as much as digits as its factorization.

21212122222091 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6332629.

The product of its (nonzero) digits is 2304, while the sum is 29.

The spelling of 21212122222091 in words is "twenty-one trillion, two hundred twelve billion, one hundred twenty-two million, two hundred twenty-two thousand, ninety-one".