21214044 has 36 divisors (see below), whose sum is σ = 55357120. Its totient is φ = 6842880.

The previous prime is 21214021. The next prime is 21214049. The reversal of 21214044 is 44041212.

It is a tau number, because it is divible by the number of its divisors (36).

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

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21214049) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 8389 + ... + 10620.

Almost surely, 2^21214044 is an apocalyptic number.

It is an amenable number.

21214044 is an abundant number, since it is smaller than the sum of its proper divisors (34143076).

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

21214044 is a wasteful number, since it uses less digits than its factorization.

21214044 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 19050 (or 19045 counting only the distinct ones).

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

The square root of 21214044 is about 4605.8706017430. The cubic root of 21214044 is about 276.8266019351.

Adding to 21214044 its reverse (44041212), we get a palindrome (65255256).

The spelling of 21214044 in words is "twenty-one million, two hundred fourteen thousand, forty-four".