21126458 has 4 divisors (see below), whose sum is σ = 31689690. Its totient is φ = 10563228.

The previous prime is 21126451. The next prime is 21126463. The reversal of 21126458 is 85462112.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in only one way, i.e., 10738729 + 10387729 = 3277^2 + 3223^2 .

It is a self number, because there is not a number n which added to its sum of digits gives 21126458.

It is not an unprimeable number, because it can be changed into a prime (21126451) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 5281613 + ... + 5281616.

Almost surely, 2^21126458 is an apocalyptic number.

21126458 is a deficient number, since it is larger than the sum of its proper divisors (10563232).

21126458 is a wasteful number, since it uses less digits than its factorization.

21126458 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10563231.

The product of its digits is 3840, while the sum is 29.

The square root of 21126458 is about 4596.3526844662. The cubic root of 21126458 is about 276.4451002644.

The spelling of 21126458 in words is "twenty-one million, one hundred twenty-six thousand, four hundred fifty-eight".