21110219993 has 2 divisors, whose sum is σ = 21110219994. Its totient is φ = 21110219992.

The previous prime is 21110219981. The next prime is 21110220029. The reversal of 21110219993 is 39991201112.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 20399837584 + 710382409 = 142828^2 + 26653^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21110219993 is a prime.

It is not a weakly prime, because it can be changed into another prime (21110219093) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10555109996 + 10555109997.

It is an arithmetic number, because the mean of its divisors is an integer number (10555109997).

Almost surely, 2^21110219993 is an apocalyptic number.

It is an amenable number.

21110219993 is a deficient number, since it is larger than the sum of its proper divisors (1).

21110219993 is an equidigital number, since it uses as much as digits as its factorization.

21110219993 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 8748, while the sum is 38.

The spelling of 21110219993 in words is "twenty-one billion, one hundred ten million, two hundred nineteen thousand, nine hundred ninety-three".