21183426 has 48 divisors (see below), whose sum is σ = 50712480. Its totient is φ = 6336960.

The previous prime is 21183389. The next prime is 21183431. The reversal of 21183426 is 62438112.

It is a self number, because there is not a number n which added to its sum of digits gives 21183426.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 15790 + ... + 17078.

It is an arithmetic number, because the mean of its divisors is an integer number (1056510).

Almost surely, 2^21183426 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21183426, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (25356240).

21183426 is an abundant number, since it is smaller than the sum of its proper divisors (29529054).

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

21183426 is a wasteful number, since it uses less digits than its factorization.

21183426 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1391 (or 1388 counting only the distinct ones).

The product of its digits is 2304, while the sum is 27.

The square root of 21183426 is about 4602.5455999914. The cubic root of 21183426 is about 276.6933575321.

It can be divided in two parts, 21183 and 426, that added together give a square (21609 = 147²).

The spelling of 21183426 in words is "twenty-one million, one hundred eighty-three thousand, four hundred twenty-six".