21343553 has 24 divisors (see below), whose sum is σ = 27170304. Its totient is φ = 16410240.

The previous prime is 21343519. The next prime is 21343579. The reversal of 21343553 is 35534312.

It is not a de Polignac number, because 21343553 - 2⁶ = 21343489 is a prime.

It is not an unprimeable number, because it can be changed into a prime (21343513) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 95600 + ... + 95822.

It is an arithmetic number, because the mean of its divisors is an integer number (1132096).

Almost surely, 2^21343553 is an apocalyptic number.

It is an amenable number.

21343553 is a deficient number, since it is larger than the sum of its proper divisors (5826751).

21343553 is a wasteful number, since it uses less digits than its factorization.

21343553 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 365 (or 354 counting only the distinct ones).

The product of its digits is 5400, while the sum is 26.

The square root of 21343553 is about 4619.9083324239. The cubic root of 21343553 is about 277.3887896772.

Adding to 21343553 its reverse (35534312), we get a palindrome (56877865).

The spelling of 21343553 in words is "twenty-one million, three hundred forty-three thousand, five hundred fifty-three".