21056042 has 16 divisors (see below), whose sum is σ = 36977472. Its totient is φ = 8803680.

The previous prime is 21056039. The next prime is 21056051. The reversal of 21056042 is 24065012.

It is a happy number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 17768 + ... + 18915.

It is an arithmetic number, because the mean of its divisors is an integer number (2311092).

Almost surely, 2^21056042 is an apocalyptic number.

21056042 is a deficient number, since it is larger than the sum of its proper divisors (15921430).

21056042 is a wasteful number, since it uses less digits than its factorization.

21056042 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 36733.

The product of its (nonzero) digits is 480, while the sum is 20.

The square root of 21056042 is about 4588.6863043795. The cubic root of 21056042 is about 276.1376212779.

The spelling of 21056042 in words is "twenty-one million, fifty-six thousand, forty-two".