21103299991 has 2 divisors, whose sum is σ = 21103299992. Its totient is φ = 21103299990.

The previous prime is 21103299961. The next prime is 21103300033. The reversal of 21103299991 is 19999230112.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 21103299991 - 2¹³ = 21103291799 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21103299961) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10551649995 + 10551649996.

It is an arithmetic number, because the mean of its divisors is an integer number (10551649996).

Almost surely, 2^21103299991 is an apocalyptic number.

21103299991 is a deficient number, since it is larger than the sum of its proper divisors (1).

21103299991 is an equidigital number, since it uses as much as digits as its factorization.

21103299991 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 78732, while the sum is 46.

The spelling of 21103299991 in words is "twenty-one billion, one hundred three million, two hundred ninety-nine thousand, nine hundred ninety-one".