21112220993 has 2 divisors, whose sum is σ = 21112220994. Its totient is φ = 21112220992.

The previous prime is 21112220989. The next prime is 21112221023. The reversal of 21112220993 is 39902221112.

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., 14950441984 + 6161779009 = 122272^2 + 78497^2 .

It is a cyclic number.

It is not a de Polignac number, because 21112220993 - 2² = 21112220989 is a prime.

It is not a weakly prime, because it can be changed into another prime (21112220293) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10556110496 + 10556110497.

It is an arithmetic number, because the mean of its divisors is an integer number (10556110497).

Almost surely, 2^21112220993 is an apocalyptic number.

It is an amenable number.

21112220993 is a deficient number, since it is larger than the sum of its proper divisors (1).

21112220993 is an equidigital number, since it uses as much as digits as its factorization.

21112220993 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 3888, while the sum is 32.

The spelling of 21112220993 in words is "twenty-one billion, one hundred twelve million, two hundred twenty thousand, nine hundred ninety-three".