21112211993 has 2 divisors, whose sum is σ = 21112211994. Its totient is φ = 21112211992.

The previous prime is 21112211941. The next prime is 21112212067. The reversal of 21112211993 is 39911221112.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 20092495504 + 1019716489 = 141748^2 + 31933^2 .

It is a cyclic number.

It is not a de Polignac number, because 21112211993 - 2⁶ = 21112211929 is a prime.

It is not a weakly prime, because it can be changed into another prime (21112211293) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10556105996 + 10556105997.

It is an arithmetic number, because the mean of its divisors is an integer number (10556105997).

Almost surely, 2^21112211993 is an apocalyptic number.

It is an amenable number.

21112211993 is a deficient number, since it is larger than the sum of its proper divisors (1).

21112211993 is an equidigital number, since it uses as much as digits as its factorization.

21112211993 is an evil number, because the sum of its binary digits is even.

The product of its digits is 1944, while the sum is 32.

The spelling of 21112211993 in words is "twenty-one billion, one hundred twelve million, two hundred eleven thousand, nine hundred ninety-three".