21101099989 has 2 divisors, whose sum is σ = 21101099990. Its totient is φ = 21101099988.

The previous prime is 21101099983. The next prime is 21101100061. The reversal of 21101099989 is 98999010112.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 20111494225 + 989605764 = 141815^2 + 31458^2 .

It is a cyclic number.

It is not a de Polignac number, because 21101099989 - 2¹⁹ = 21100575701 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21101099983) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10550549994 + 10550549995.

It is an arithmetic number, because the mean of its divisors is an integer number (10550549995).

Almost surely, 2^21101099989 is an apocalyptic number.

It is an amenable number.

21101099989 is a deficient number, since it is larger than the sum of its proper divisors (1).

21101099989 is an equidigital number, since it uses as much as digits as its factorization.

21101099989 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 104976, while the sum is 49.

The spelling of 21101099989 in words is "twenty-one billion, one hundred one million, ninety-nine thousand, nine hundred eighty-nine".