21446819 has 2 divisors, whose sum is σ = 21446820. Its totient is φ = 21446818.

The previous prime is 21446783. The next prime is 21446837. The reversal of 21446819 is 91864412.

It is a happy number.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 21446819 - 2²⁰ = 20398243 is a prime.

It is a super-2 number, since 2×21446819² = 919932090437522, which contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (21446849) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10723409 + 10723410.

It is an arithmetic number, because the mean of its divisors is an integer number (10723410).

Almost surely, 2^21446819 is an apocalyptic number.

21446819 is a deficient number, since it is larger than the sum of its proper divisors (1).

21446819 is an equidigital number, since it uses as much as digits as its factorization.

21446819 is an evil number, because the sum of its binary digits is even.

The product of its digits is 13824, while the sum is 35.

The square root of 21446819 is about 4631.0710424264. The cubic root of 21446819 is about 277.8354312982.

The spelling of 21446819 in words is "twenty-one million, four hundred forty-six thousand, eight hundred nineteen".