21343519 has 2 divisors, whose sum is σ = 21343520. Its totient is φ = 21343518.

The previous prime is 21343513. The next prime is 21343579. The reversal of 21343519 is 91534312.

It is a weak prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21343519 is a prime.

It is a super-2 number, since 2×21343519² = 911091606606722, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21343513) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10671759 + 10671760.

It is an arithmetic number, because the mean of its divisors is an integer number (10671760).

Almost surely, 2^21343519 is an apocalyptic number.

21343519 is a deficient number, since it is larger than the sum of its proper divisors (1).

21343519 is an equidigital number, since it uses as much as digits as its factorization.

21343519 is an evil number, because the sum of its binary digits is even.

The product of its digits is 3240, while the sum is 28.

The square root of 21343519 is about 4619.9046526958. The cubic root of 21343519 is about 277.3886423849.

The spelling of 21343519 in words is "twenty-one million, three hundred forty-three thousand, five hundred nineteen".