21619459 has 2 divisors, whose sum is σ = 21619460. Its totient is φ = 21619458.

The previous prime is 21619447. The next prime is 21619463. The reversal of 21619459 is 95491612.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 21619459 - 2¹¹ = 21617411 is a prime.

It is not a weakly prime, because it can be changed into another prime (21619439) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10809729 + 10809730.

It is an arithmetic number, because the mean of its divisors is an integer number (10809730).

Almost surely, 2^21619459 is an apocalyptic number.

21619459 is a deficient number, since it is larger than the sum of its proper divisors (1).

21619459 is an equidigital number, since it uses as much as digits as its factorization.

21619459 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 19440, while the sum is 37.

The square root of 21619459 is about 4649.6729992549. The cubic root of 21619459 is about 278.5789351723.

The spelling of 21619459 in words is "twenty-one million, six hundred nineteen thousand, four hundred fifty-nine".