21075042 has 16 divisors (see below), whose sum is σ = 42243840. Its totient is φ = 7009392.

The previous prime is 21075037. The next prime is 21075049. The reversal of 21075042 is 24057012.

It is not an unprimeable number, because it can be changed into a prime (21075049) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 793 + ... + 6540.

It is an arithmetic number, because the mean of its divisors is an integer number (2640240).

Almost surely, 2^21075042 is an apocalyptic number.

21075042 is an abundant number, since it is smaller than the sum of its proper divisors (21168798).

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

21075042 is a wasteful number, since it uses less digits than its factorization.

21075042 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7817.

The product of its (nonzero) digits is 560, while the sum is 21.

The square root of 21075042 is about 4590.7561468673. The cubic root of 21075042 is about 276.2206542539.

The spelling of 21075042 in words is "twenty-one million, seventy-five thousand, forty-two".