21110110913 has 2 divisors, whose sum is σ = 21110110914. Its totient is φ = 21110110912.

The previous prime is 21110110891. The next prime is 21110110939. The reversal of 21110110913 is 31901101112.

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., 19585442704 + 1524668209 = 139948^2 + 39047^2 .

It is a cyclic number.

It is not a de Polignac number, because 21110110913 - 2⁶ = 21110110849 is a prime.

It is not a weakly prime, because it can be changed into another prime (21110110313) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10555055456 + 10555055457.

It is an arithmetic number, because the mean of its divisors is an integer number (10555055457).

Almost surely, 2^21110110913 is an apocalyptic number.

It is an amenable number.

21110110913 is a deficient number, since it is larger than the sum of its proper divisors (1).

21110110913 is an equidigital number, since it uses as much as digits as its factorization.

21110110913 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 54, while the sum is 20.

The spelling of 21110110913 in words is "twenty-one billion, one hundred ten million, one hundred ten thousand, nine hundred thirteen".