21100110989 has 2 divisors, whose sum is σ = 21100110990. Its totient is φ = 21100110988.

The previous prime is 21100110979. The next prime is 21100111009. The reversal of 21100110989 is 98901100112.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 15554330089 + 5545780900 = 124717^2 + 74470^2 .

It is a cyclic number.

It is not a de Polignac number, because 21100110989 - 2¹² = 21100106893 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21100110979) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10550055494 + 10550055495.

It is an arithmetic number, because the mean of its divisors is an integer number (10550055495).

Almost surely, 2^21100110989 is an apocalyptic number.

It is an amenable number.

21100110989 is a deficient number, since it is larger than the sum of its proper divisors (1).

21100110989 is an equidigital number, since it uses as much as digits as its factorization.

21100110989 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 1296, while the sum is 32.

The spelling of 21100110989 in words is "twenty-one billion, one hundred million, one hundred ten thousand, nine hundred eighty-nine".