21120022011997 has 2 divisors, whose sum is σ = 21120022011998. Its totient is φ = 21120022011996.

The previous prime is 21120022011953. The next prime is 21120022012091. The reversal of 21120022011997 is 79911022002112.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 21055378440996 + 64643571001 = 4588614^2 + 254251^2 .

It is a cyclic number.

It is not a de Polignac number, because 21120022011997 - 2⁴³ = 12323928989789 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21120022011917) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10560011005998 + 10560011005999.

It is an arithmetic number, because the mean of its divisors is an integer number (10560011005999).

Almost surely, 2^{21120022011997} is an apocalyptic number.

It is an amenable number.

21120022011997 is a deficient number, since it is larger than the sum of its proper divisors (1).

21120022011997 is an equidigital number, since it uses as much as digits as its factorization.

21120022011997 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 9072, while the sum is 37.

The spelling of 21120022011997 in words is "twenty-one trillion, one hundred twenty billion, twenty-two million, eleven thousand, nine hundred ninety-seven".