12021009991 has 2 divisors, whose sum is σ = 12021009992. Its totient is φ = 12021009990.

The previous prime is 12021009983. The next prime is 12021009997. The reversal of 12021009991 is 19990012021.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 12021009991 - 2³ = 12021009983 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (12021009997) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 6010504995 + 6010504996.

It is an arithmetic number, because the mean of its divisors is an integer number (6010504996).

Almost surely, 2^12021009991 is an apocalyptic number.

12021009991 is a deficient number, since it is larger than the sum of its proper divisors (1).

12021009991 is an equidigital number, since it uses as much as digits as its factorization.

12021009991 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 2916, while the sum is 34.

The spelling of 12021009991 in words is "twelve billion, twenty-one million, nine thousand, nine hundred ninety-one".