21811426 has 64 divisors (see below), whose sum is σ = 42900480. Its totient is φ = 8087040.

The previous prime is 21811423. The next prime is 21811481. The reversal of 21811426 is 62411812.

It is a self number, because there is not a number n which added to its sum of digits gives 21811426.

It is not an unprimeable number, because it can be changed into a prime (21811421) 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 31 ways as a sum of consecutive naturals, for example, 276055 + ... + 276133.

It is an arithmetic number, because the mean of its divisors is an integer number (670320).

Almost surely, 2^21811426 is an apocalyptic number.

21811426 is a gapful number since it is divisible by the number (26) formed by its first and last digit.

21811426 is a deficient number, since it is larger than the sum of its proper divisors (21089054).

21811426 is a wasteful number, since it uses less digits than its factorization.

21811426 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 179.

The product of its digits is 768, while the sum is 25.

The square root of 21811426 is about 4670.2704418481. The cubic root of 21811426 is about 279.4010410858.

The spelling of 21811426 in words is "twenty-one million, eight hundred eleven thousand, four hundred twenty-six".