21444412 has 24 divisors (see below), whose sum is σ = 43349040. Its totient is φ = 9173760.

The previous prime is 21444389. The next prime is 21444413.

21444412 is nontrivially palindromic in base 10.

It is a Harshad number since it is a multiple of its sum of digits (22).

It is a nude number because it is divisible by every one of its digits.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21444413) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 13587 + ... + 15082.

It is an arithmetic number, because the mean of its divisors is an integer number (1806210).

Almost surely, 2^21444412 is an apocalyptic number.

21444412 is a gapful number since it is divisible by the number (22) formed by its first and last digit.

It is an amenable number.

21444412 is an abundant number, since it is smaller than the sum of its proper divisors (21904628).

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

21444412 is a wasteful number, since it uses less digits than its factorization.

21444412 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 28701 (or 28699 counting only the distinct ones).

The product of its digits is 1024, while the sum is 22.

The square root of 21444412 is about 4630.8111600453. The cubic root of 21444412 is about 277.8250369844.

It can be divided in two parts, 2144 and 4412, that added together give a palindrome (6556).

The spelling of 21444412 in words is "twenty-one million, four hundred forty-four thousand, four hundred twelve".