21118619 has 2 divisors, whose sum is σ = 21118620. Its totient is φ = 21118618.

The previous prime is 21118613. The next prime is 21118661. The reversal of 21118619 is 91681112.

It is a weak prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21118619 is a prime.

It is a super-2 number, since 2×21118619² = 891992136934322, which contains 22 as substring.

It is a Chen prime.

It is a junction number, because it is equal to n+sod(n) for n = 21118591 and 21118600.

It is not a weakly prime, because it can be changed into another prime (21118613) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10559309 + 10559310.

It is an arithmetic number, because the mean of its divisors is an integer number (10559310).

Almost surely, 2^21118619 is an apocalyptic number.

21118619 is a deficient number, since it is larger than the sum of its proper divisors (1).

21118619 is an equidigital number, since it uses as much as digits as its factorization.

21118619 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 864, while the sum is 29.

The square root of 21118619 is about 4595.4998639974. The cubic root of 21118619 is about 276.4109042620.

The spelling of 21118619 in words is "twenty-one million, one hundred eighteen thousand, six hundred nineteen".