21073242 has 64 divisors (see below), whose sum is σ = 47001600. Its totient is φ = 6272640.

The previous prime is 21073201. The next prime is 21073253. The reversal of 21073242 is 24237012.

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 31 ways as a sum of consecutive naturals, for example, 236734 + ... + 236822.

It is an arithmetic number, because the mean of its divisors is an integer number (734400).

Almost surely, 2^21073242 is an apocalyptic number.

21073242 is an abundant number, since it is smaller than the sum of its proper divisors (25928358).

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

21073242 is a wasteful number, since it uses less digits than its factorization.

21073242 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 211.

The product of its (nonzero) digits is 672, while the sum is 21.

The square root of 21073242 is about 4590.5600965460. The cubic root of 21073242 is about 276.2127901125.

The spelling of 21073242 in words is "twenty-one million, seventy-three thousand, two hundred forty-two".