21255419 has 2 divisors, whose sum is σ = 21255420. Its totient is φ = 21255418.

The previous prime is 21255407. The next prime is 21255431. The reversal of 21255419 is 91455212.

It is a balanced prime because it is at equal distance from previous prime (21255407) and next prime (21255431).

It is a cyclic number.

It is not a de Polignac number, because 21255419 - 2²⁴ = 4478203 is a prime.

It is a super-2 number, since 2×21255419² = 903585673731122, which contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 21255391 and 21255400.

It is not a weakly prime, because it can be changed into another prime (21255439) 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, 10627709 + 10627710.

It is an arithmetic number, because the mean of its divisors is an integer number (10627710).

Almost surely, 2^21255419 is an apocalyptic number.

21255419 is a deficient number, since it is larger than the sum of its proper divisors (1).

21255419 is an equidigital number, since it uses as much as digits as its factorization.

21255419 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 3600, while the sum is 29.

The square root of 21255419 is about 4610.3599642544. The cubic root of 21255419 is about 277.0064554704.

The spelling of 21255419 in words is "twenty-one million, two hundred fifty-five thousand, four hundred nineteen".