21441810 has 32 divisors (see below), whose sum is σ = 55419840. Its totient is φ = 5277888.

The previous prime is 21441769. The next prime is 21441857. The reversal of 21441810 is 1814412.

It is a happy number.

It is a super-2 number, since 2×21441810² = 919502432152200, which contains 22 as substring.

It is an unprimeable number.

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 15 ways as a sum of consecutive naturals, for example, 27100 + ... + 27879.

It is an arithmetic number, because the mean of its divisors is an integer number (1731870).

Almost surely, 2^21441810 is an apocalyptic number.

21441810 is an abundant number, since it is smaller than the sum of its proper divisors (33978030).

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

21441810 is a wasteful number, since it uses less digits than its factorization.

21441810 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 55002.

The product of its (nonzero) digits is 256, while the sum is 21.

The square root of 21441810 is about 4630.5302072225. The cubic root of 21441810 is about 277.8137997137.

It can be divided in two parts, 214 and 41810, that added together give a palindrome (42024).

The spelling of 21441810 in words is "twenty-one million, four hundred forty-one thousand, eight hundred ten".