21412044 has 72 divisors (see below), whose sum is σ = 58378320. Its totient is φ = 6592512.

The previous prime is 21412033. The next prime is 21412049. The reversal of 21412044 is 44021412.

It is a Harshad number since it is a multiple of its sum of digits (18).

It is not an unprimeable number, because it can be changed into a prime (21412049) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 35812 + ... + 36404.

It is an arithmetic number, because the mean of its divisors is an integer number (810810).

Almost surely, 2^21412044 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21412044, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (29189160).

21412044 is an abundant number, since it is smaller than the sum of its proper divisors (36966276).

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

21412044 is a wasteful number, since it uses less digits than its factorization.

21412044 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 679 (or 674 counting only the distinct ones).

The product of its (nonzero) digits is 256, while the sum is 18.

The square root of 21412044 is about 4627.3149881978. The cubic root of 21412044 is about 277.6851844039.

Adding to 21412044 its reverse (44021412), we get a palindrome (65433456).

The spelling of 21412044 in words is "twenty-one million, four hundred twelve thousand, forty-four".