21450442 has 8 divisors (see below), whose sum is σ = 34650756. Its totient is φ = 9900192.

The previous prime is 21450433. The next prime is 21450461. The reversal of 21450442 is 24405412.

It is a happy number.

It can be written as a sum of positive squares in 2 ways, for example, as 21427641 + 22801 = 4629^2 + 151^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is an unprimeable number.

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, 412483 + ... + 412534.

Almost surely, 2^21450442 is an apocalyptic number.

21450442 is a deficient number, since it is larger than the sum of its proper divisors (13200314).

21450442 is a wasteful number, since it uses less digits than its factorization.

21450442 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 825032.

The product of its (nonzero) digits is 1280, while the sum is 22.

The square root of 21450442 is about 4631.4621881216. The cubic root of 21450442 is about 277.8510752824.

Adding to 21450442 its reverse (24405412), we get a palindrome (45855854).

The spelling of 21450442 in words is "twenty-one million, four hundred fifty thousand, four hundred forty-two".