21626219 has 2 divisors, whose sum is σ = 21626220. Its totient is φ = 21626218.

The previous prime is 21626207. The next prime is 21626281. The reversal of 21626219 is 91262612.

It is a happy number.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 21626219 - 2⁴ = 21626203 is a prime.

It is a super-2 number, since 2×21626219² = 935386696471922, which contains 22 as substring.

It is a Sophie Germain prime.

It is a junction number, because it is equal to n+sod(n) for n = 21626191 and 21626200.

It is not a weakly prime, because it can be changed into another prime (21626419) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10813109 + 10813110.

It is an arithmetic number, because the mean of its divisors is an integer number (10813110).

Almost surely, 2^21626219 is an apocalyptic number.

21626219 is a deficient number, since it is larger than the sum of its proper divisors (1).

21626219 is an equidigital number, since it uses as much as digits as its factorization.

21626219 is an evil number, because the sum of its binary digits is even.

The product of its digits is 2592, while the sum is 29.

The square root of 21626219 is about 4650.3998752795. The cubic root of 21626219 is about 278.6079676188.

The spelling of 21626219 in words is "twenty-one million, six hundred twenty-six thousand, two hundred nineteen".