21442416 has 20 divisors (see below), whose sum is σ = 55393032. Its totient is φ = 7147456.

The previous prime is 21442411. The next prime is 21442427. The reversal of 21442416 is 61424412.

It is a happy number.

It is a Harshad number since it is a multiple of its sum of digits (24).

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 (21442411) 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 3 ways as a sum of consecutive naturals, for example, 223311 + ... + 223406.

Almost surely, 2^21442416 is an apocalyptic number.

It is an amenable number.

21442416 is an abundant number, since it is smaller than the sum of its proper divisors (33950616).

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

21442416 is a wasteful number, since it uses less digits than its factorization.

21442416 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 446728 (or 446722 counting only the distinct ones).

The product of its digits is 1536, while the sum is 24.

The square root of 21442416 is about 4630.5956420314. The cubic root of 21442416 is about 277.8164169302.

Adding to 21442416 its reverse (61424412), we get a palindrome (82866828).

It can be divided in two parts, 2144 and 2416, that added together give a triangular number (4560 = T₉₅).

The spelling of 21442416 in words is "twenty-one million, four hundred forty-two thousand, four hundred sixteen".