21458258 has 16 divisors (see below), whose sum is σ = 34223040. Its totient is φ = 10062000.

The previous prime is 21458257. The next prime is 21458279. The reversal of 21458258 is 85285412.

It is a happy number.

It is not an unprimeable number, because it can be changed into a prime (21458257) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1043 + ... + 6633.

It is an arithmetic number, because the mean of its divisors is an integer number (2138940).

Almost surely, 2^21458258 is an apocalyptic number.

21458258 is a deficient number, since it is larger than the sum of its proper divisors (12764782).

21458258 is a wasteful number, since it uses less digits than its factorization.

21458258 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5713.

The product of its digits is 25600, while the sum is 35.

The square root of 21458258 is about 4632.3059052701. The cubic root of 21458258 is about 277.8848184921.

The spelling of 21458258 in words is "twenty-one million, four hundred fifty-eight thousand, two hundred fifty-eight".