21003110993 has 2 divisors, whose sum is σ = 21003110994. Its totient is φ = 21003110992.

The previous prime is 21003110987. The next prime is 21003111011. The reversal of 21003110993 is 39901130012.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 16132048144 + 4871062849 = 127012^2 + 69793^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21003110993 is a prime.

It is a super-2 number, since 2×21003110993² (a number of 21 digits) contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (21003112993) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10501555496 + 10501555497.

It is an arithmetic number, because the mean of its divisors is an integer number (10501555497).

Almost surely, 2^21003110993 is an apocalyptic number.

It is an amenable number.

21003110993 is a deficient number, since it is larger than the sum of its proper divisors (1).

21003110993 is an equidigital number, since it uses as much as digits as its factorization.

21003110993 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 1458, while the sum is 29.

The spelling of 21003110993 in words is "twenty-one billion, three million, one hundred ten thousand, nine hundred ninety-three".