21798113 has 2 divisors, whose sum is σ = 21798114. Its totient is φ = 21798112.

The previous prime is 21798107. The next prime is 21798137. The reversal of 21798113 is 31189712.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 13601344 + 8196769 = 3688^2 + 2863^2 .

It is a cyclic number.

It is not a de Polignac number, because 21798113 - 2⁸ = 21797857 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 21798113.

It is not a weakly prime, because it can be changed into another prime (21798163) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10899056 + 10899057.

It is an arithmetic number, because the mean of its divisors is an integer number (10899057).

Almost surely, 2^21798113 is an apocalyptic number.

It is an amenable number.

21798113 is a deficient number, since it is larger than the sum of its proper divisors (1).

21798113 is an equidigital number, since it uses as much as digits as its factorization.

21798113 is an evil number, because the sum of its binary digits is even.

The product of its digits is 3024, while the sum is 32.

The square root of 21798113 is about 4668.8449321004. The cubic root of 21798113 is about 279.3441836829.

The spelling of 21798113 in words is "twenty-one million, seven hundred ninety-eight thousand, one hundred thirteen".