21126558 has 32 divisors (see below), whose sum is σ = 45619200. Its totient is φ = 6502496.

The previous prime is 21126551. The next prime is 21126569. The reversal of 21126558 is 85562112.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21126551) 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 15 ways as a sum of consecutive naturals, for example, 1363 + ... + 6641.

It is an arithmetic number, because the mean of its divisors is an integer number (1425600).

Almost surely, 2^21126558 is an apocalyptic number.

21126558 is an abundant number, since it is smaller than the sum of its proper divisors (24492642).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

21126558 is a wasteful number, since it uses less digits than its factorization.

21126558 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5336.

The product of its digits is 4800, while the sum is 30.

The square root of 21126558 is about 4596.3635626438. The cubic root of 21126558 is about 276.4455364389.

The spelling of 21126558 in words is "twenty-one million, one hundred twenty-six thousand, five hundred fifty-eight".