12020221991 has 2 divisors, whose sum is σ = 12020221992. Its totient is φ = 12020221990.

The previous prime is 12020221957. The next prime is 12020222003. The reversal of 12020221991 is 19912202021.

It is a strong prime.

It is an emirp because it is prime and its reverse (19912202021) is a distict prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-12020221991 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (12020221901) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 6010110995 + 6010110996.

It is an arithmetic number, because the mean of its divisors is an integer number (6010110996).

Almost surely, 2^12020221991 is an apocalyptic number.

12020221991 is a deficient number, since it is larger than the sum of its proper divisors (1).

12020221991 is an equidigital number, since it uses as much as digits as its factorization.

12020221991 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 1296, while the sum is 29.

The spelling of 12020221991 in words is "twelve billion, twenty million, two hundred twenty-one thousand, nine hundred ninety-one".