221200021993 has 2 divisors, whose sum is σ = 221200021994. Its totient is φ = 221200021992.

The previous prime is 221200021937. The next prime is 221200022033. The reversal of 221200021993 is 399120002122.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 217703428569 + 3496593424 = 466587^2 + 59132^2 .

It is a cyclic number.

It is not a de Polignac number, because 221200021993 - 2⁹ = 221200021481 is a prime.

It is not a weakly prime, because it can be changed into another prime (221200021193) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 110600010996 + 110600010997.

It is an arithmetic number, because the mean of its divisors is an integer number (110600010997).

Almost surely, 2^221200021993 is an apocalyptic number.

It is an amenable number.

221200021993 is a deficient number, since it is larger than the sum of its proper divisors (1).

221200021993 is an equidigital number, since it uses as much as digits as its factorization.

221200021993 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 3888, while the sum is 31.

The spelling of 221200021993 in words is "two hundred twenty-one billion, two hundred million, twenty-one thousand, nine hundred ninety-three".