21240458 has 8 divisors (see below), whose sum is σ = 31880928. Its totient is φ = 10613484.

The previous prime is 21240433. The next prime is 21240511. The reversal of 21240458 is 85404212.

It is a happy number.

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

It is a Curzon number.

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, 2885 + ... + 7127.

It is an arithmetic number, because the mean of its divisors is an integer number (3985116).

Almost surely, 2^21240458 is an apocalyptic number.

21240458 is a deficient number, since it is larger than the sum of its proper divisors (10640470).

21240458 is a wasteful number, since it uses less digits than its factorization.

21240458 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6748.

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

The square root of 21240458 is about 4608.7371372210. The cubic root of 21240458 is about 276.9414482628.

The spelling of 21240458 in words is "twenty-one million, two hundred forty thousand, four hundred fifty-eight".