21120442 has 16 divisors (see below), whose sum is σ = 36328320. Its totient is φ = 9021168.

The previous prime is 21120431. The next prime is 21120461. The reversal of 21120442 is 24402112.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 2059 + ... + 6817.

It is an arithmetic number, because the mean of its divisors is an integer number (2270520).

Almost surely, 2^21120442 is an apocalyptic number.

21120442 is a deficient number, since it is larger than the sum of its proper divisors (15207878).

21120442 is a wasteful number, since it uses less digits than its factorization.

21120442 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5085.

The product of its (nonzero) digits is 128, while the sum is 16.

The square root of 21120442 is about 4595.6982059313. The cubic root of 21120442 is about 276.4188574743.

Adding to 21120442 its reverse (24402112), we get a palindrome (45522554).

The spelling of 21120442 in words is "twenty-one million, one hundred twenty thousand, four hundred forty-two".