21223519 has 2 divisors, whose sum is σ = 21223520. Its totient is φ = 21223518.

The previous prime is 21223511. The next prime is 21223583. The reversal of 21223519 is 91532212.

It is a happy number.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 21223519 - 2³ = 21223511 is a prime.

It is a super-2 number, since 2×21223519² = 900875517486722, which contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 21223493 and 21223502.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21223511) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10611759 + 10611760.

It is an arithmetic number, because the mean of its divisors is an integer number (10611760).

Almost surely, 2^21223519 is an apocalyptic number.

21223519 is a deficient number, since it is larger than the sum of its proper divisors (1).

21223519 is an equidigital number, since it uses as much as digits as its factorization.

21223519 is an evil number, because the sum of its binary digits is even.

The product of its digits is 1080, while the sum is 25.

The square root of 21223519 is about 4606.8990655320. The cubic root of 21223519 is about 276.8678095686.

The spelling of 21223519 in words is "twenty-one million, two hundred twenty-three thousand, five hundred nineteen".