12021210021991 has 2 divisors, whose sum is σ = 12021210021992. Its totient is φ = 12021210021990.

The previous prime is 12021210021979. The next prime is 12021210022079. The reversal of 12021210021991 is 19912001212021.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 12021210021991 - 2⁵ = 12021210021959 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (12021210028991) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 6010605010995 + 6010605010996.

It is an arithmetic number, because the mean of its divisors is an integer number (6010605010996).

Almost surely, 2^{12021210021991} is an apocalyptic number.

12021210021991 is a deficient number, since it is larger than the sum of its proper divisors (1).

12021210021991 is an equidigital number, since it uses as much as digits as its factorization.

12021210021991 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 1296, while the sum is 31.

The spelling of 12021210021991 in words is "twelve trillion, twenty-one billion, two hundred ten million, twenty-one thousand, nine hundred ninety-one".