21345838 has 8 divisors (see below), whose sum is σ = 32059440. Its totient is φ = 10659360.

The previous prime is 21345809. The next prime is 21345839. The reversal of 21345838 is 83854312.

It is a happy number.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21345839) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 4683 + ... + 8038.

It is an arithmetic number, because the mean of its divisors is an integer number (4007430).

Almost surely, 2^21345838 is an apocalyptic number.

21345838 is a deficient number, since it is larger than the sum of its proper divisors (10713602).

21345838 is a wasteful number, since it uses less digits than its factorization.

21345838 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 13562.

The product of its digits is 23040, while the sum is 34.

The square root of 21345838 is about 4620.1556250845. The cubic root of 21345838 is about 277.3986882285.

The spelling of 21345838 in words is "twenty-one million, three hundred forty-five thousand, eight hundred thirty-eight".