21404334 has 32 divisors (see below), whose sum is σ = 49061376. Its totient is φ = 6098400.

The previous prime is 21404321. The next prime is 21404359. The reversal of 21404334 is 43340412.

It is a Harshad number since it is a multiple of its sum of digits (21).

It is a plaindrome in base 16.

It is a self number, because there is not a number n which added to its sum of digits gives 21404334.

It is a congruent number.

It is an unprimeable number.

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 15 ways as a sum of consecutive naturals, for example, 29079 + ... + 29805.

It is an arithmetic number, because the mean of its divisors is an integer number (1533168).

Almost surely, 2^21404334 is an apocalyptic number.

21404334 is an abundant number, since it is smaller than the sum of its proper divisors (27657042).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

21404334 is a wasteful number, since it uses less digits than its factorization.

21404334 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1440.

The product of its (nonzero) digits is 1152, while the sum is 21.

The square root of 21404334 is about 4626.4818166724. The cubic root of 21404334 is about 277.6518509866.

Adding to 21404334 its reverse (43340412), we get a palindrome (64744746).

The spelling of 21404334 in words is "twenty-one million, four hundred four thousand, three hundred thirty-four".