21106442 has 8 divisors (see below), whose sum is σ = 36182496. Its totient is φ = 9045612.

The previous prime is 21106441. The next prime is 21106447. The reversal of 21106442 is 24460112.

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

It is not an unprimeable number, because it can be changed into a prime (21106441) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 753788 + ... + 753815.

It is an arithmetic number, because the mean of its divisors is an integer number (4522812).

Almost surely, 2^21106442 is an apocalyptic number.

21106442 is a deficient number, since it is larger than the sum of its proper divisors (15076054).

21106442 is a wasteful number, since it uses less digits than its factorization.

21106442 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1507612.

The product of its (nonzero) digits is 384, while the sum is 20.

The square root of 21106442 is about 4594.1747898834. The cubic root of 21106442 is about 276.3577678534.

Adding to 21106442 its reverse (24460112), we get a palindrome (45566554).

It can be divided in two parts, 211064 and 42, that multiplied together give a palindrome (8864688).

The spelling of 21106442 in words is "twenty-one million, one hundred six thousand, four hundred forty-two".