21442410 has 96 divisors (see below), whose sum is σ = 61663680. Its totient is φ = 5169120.

The previous prime is 21442391. The next prime is 21442411. The reversal of 21442410 is 1424412.

21442410 is a `hidden beast` number, since 214 + 42 + 410 = 666.

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 (21442411) by changing a digit.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 119701 + ... + 119879.

It is an arithmetic number, because the mean of its divisors is an integer number (642330).

Almost surely, 2^21442410 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21442410, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (30831840).

21442410 is an abundant number, since it is smaller than the sum of its proper divisors (40221270).

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

21442410 is a wasteful number, since it uses less digits than its factorization.

21442410 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 225 (or 200 counting only the distinct ones).

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

The square root of 21442410 is about 4630.5949941665. The cubic root of 21442410 is about 277.8163910174.

Adding to 21442410 its reverse (1424412), we get a palindrome (22866822).

It can be divided in two parts, 2144 and 2410, that added together give a palindrome (4554).

The spelling of 21442410 in words is "twenty-one million, four hundred forty-two thousand, four hundred ten".