21042458 has 8 divisors (see below), whose sum is σ = 32652180. Its totient is φ = 10158400.

The previous prime is 21042457. The next prime is 21042467. The reversal of 21042458 is 85424012.

It is a happy number.

It can be written as a sum of positive squares in 2 ways, for example, as 18722929 + 2319529 = 4327^2 + 1523^2 .

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 (21042457) 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, 181343 + ... + 181458.

Almost surely, 2^21042458 is an apocalyptic number.

21042458 is a deficient number, since it is larger than the sum of its proper divisors (11609722).

21042458 is a wasteful number, since it uses less digits than its factorization.

21042458 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 362832.

The product of its (nonzero) digits is 2560, while the sum is 26.

The square root of 21042458 is about 4587.2059033795. The cubic root of 21042458 is about 276.0782264435.

The spelling of 21042458 in words is "twenty-one million, forty-two thousand, four hundred fifty-eight".