1212021100091 has 4 divisors (see below), whose sum is σ = 1212073812792. Its totient is φ = 1211968387392.

The previous prime is 1212021100027. The next prime is 1212021100097. The reversal of 1212021100091 is 1900011202121.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 1212021100091 - 2⁶ = 1212021100027 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1212021100097) 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 3 ways as a sum of consecutive naturals, for example, 26321846 + ... + 26367851.

It is an arithmetic number, because the mean of its divisors is an integer number (303018453198).

Almost surely, 2^{1212021100091} is an apocalyptic number.

1212021100091 is a deficient number, since it is larger than the sum of its proper divisors (52712701).

1212021100091 is an equidigital number, since it uses as much as digits as its factorization.

1212021100091 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 52712700.

The product of its (nonzero) digits is 72, while the sum is 20.

The spelling of 1212021100091 in words is "one trillion, two hundred twelve billion, twenty-one million, one hundred thousand, ninety-one".