21579842 has 8 divisors (see below), whose sum is σ = 33777216. Its totient is φ = 10320772.

The previous prime is 21579827. The next prime is 21579853. The reversal of 21579842 is 24897512.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a junction number, because it is equal to n+sod(n) for n = 21579796 and 21579805.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 234518 + ... + 234609.

It is an arithmetic number, because the mean of its divisors is an integer number (4222152).

Almost surely, 2^21579842 is an apocalyptic number.

21579842 is a deficient number, since it is larger than the sum of its proper divisors (12197374).

21579842 is a wasteful number, since it uses less digits than its factorization.

21579842 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 469152.

The product of its digits is 40320, while the sum is 38.

The square root of 21579842 is about 4645.4108537351. The cubic root of 21579842 is about 278.4086686565.

The spelling of 21579842 in words is "twenty-one million, five hundred seventy-nine thousand, eight hundred forty-two".