12166157021 has 2 divisors, whose sum is σ = 12166157022. Its totient is φ = 12166157020.

The previous prime is 12166156999. The next prime is 12166157051. The reversal of 12166157021 is 12075166121.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 11082825625 + 1083331396 = 105275^2 + 32914^2 .

It is a cyclic number.

It is not a de Polignac number, because 12166157021 - 2⁶ = 12166156957 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (12166157051) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 6083078510 + 6083078511.

It is an arithmetic number, because the mean of its divisors is an integer number (6083078511).

Almost surely, 2^12166157021 is an apocalyptic number.

It is an amenable number.

12166157021 is a deficient number, since it is larger than the sum of its proper divisors (1).

12166157021 is an equidigital number, since it uses as much as digits as its factorization.

12166157021 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 5040, while the sum is 32.

The spelling of 12166157021 in words is "twelve billion, one hundred sixty-six million, one hundred fifty-seven thousand, twenty-one".