21343424 has 14 divisors (see below), whose sum is σ = 42353484. Its totient is φ = 10671680.

The previous prime is 21343373. The next prime is 21343429. The reversal of 21343424 is 42434312.

It is a self number, because there is not a number n which added to its sum of digits gives 21343424.

It is not an unprimeable number, because it can be changed into a prime (21343429) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 166682 + ... + 166809.

Almost surely, 2^21343424 is an apocalyptic number.

It is an amenable number.

21343424 is a deficient number, since it is larger than the sum of its proper divisors (21010060).

21343424 is an equidigital number, since it uses as much as digits as its factorization.

21343424 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 333503 (or 333493 counting only the distinct ones).

The product of its digits is 2304, while the sum is 23.

The square root of 21343424 is about 4619.8943710869. The cubic root of 21343424 is about 277.3882308320.

Adding to 21343424 its reverse (42434312), we get a palindrome (63777736).

The spelling of 21343424 in words is "twenty-one million, three hundred forty-three thousand, four hundred twenty-four".