21182719 has 2 divisors, whose sum is σ = 21182720. Its totient is φ = 21182718.

The previous prime is 21182717. The next prime is 21182723. The reversal of 21182719 is 91728112.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 21182719 - 2¹ = 21182717 is a prime.

It is a super-2 number, since 2×21182719² = 897415168465922, which contains 22 as substring.

Together with 21182717, it forms a pair of twin primes.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21182717) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10591359 + 10591360.

It is an arithmetic number, because the mean of its divisors is an integer number (10591360).

Almost surely, 2^21182719 is an apocalyptic number.

21182719 is a deficient number, since it is larger than the sum of its proper divisors (1).

21182719 is an equidigital number, since it uses as much as digits as its factorization.

21182719 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 2016, while the sum is 31.

The square root of 21182719 is about 4602.4687940278. The cubic root of 21182719 is about 276.6902792705.

The spelling of 21182719 in words is "twenty-one million, one hundred eighty-two thousand, seven hundred nineteen".