21343365 has 64 divisors (see below), whose sum is σ = 40953600. Its totient is φ = 10513152.

The previous prime is 21343363. The next prime is 21343373. The reversal of 21343365 is 56334312.

It is a happy number.

It is not a de Polignac number, because 21343365 - 2¹ = 21343363 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21343363) 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 63 ways as a sum of consecutive naturals, for example, 135867 + ... + 136023.

It is an arithmetic number, because the mean of its divisors is an integer number (639900).

Almost surely, 2^21343365 is an apocalyptic number.

It is an amenable number.

21343365 is a deficient number, since it is larger than the sum of its proper divisors (19610235).

21343365 is a wasteful number, since it uses less digits than its factorization.

21343365 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 243 (or 237 counting only the distinct ones).

The product of its digits is 6480, while the sum is 27.

The square root of 21343365 is about 4619.8879856551. The cubic root of 21343365 is about 277.3879752354.

Adding to 21343365 its product of digits (6480), we get a triangular number (21349845 = T₆₅₃₄).

Adding to 21343365 its reverse (56334312), we get a palindrome (77677677).

The spelling of 21343365 in words is "twenty-one million, three hundred forty-three thousand, three hundred sixty-five".