21132558 has 12 divisors (see below), whose sum is σ = 45787248. Its totient is φ = 7044180.

The previous prime is 21132557. The next prime is 21132569. The reversal of 21132558 is 85523112.

It is a happy number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21132557) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 586998 + ... + 587033.

It is an arithmetic number, because the mean of its divisors is an integer number (3815604).

Almost surely, 2^21132558 is an apocalyptic number.

21132558 is an abundant number, since it is smaller than the sum of its proper divisors (24654690).

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

21132558 is a wasteful number, since it uses less digits than its factorization.

21132558 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1174039 (or 1174036 counting only the distinct ones).

The product of its digits is 2400, while the sum is 27.

The square root of 21132558 is about 4597.0162061929. The cubic root of 21132558 is about 276.4717043902.

The spelling of 21132558 in words is "twenty-one million, one hundred thirty-two thousand, five hundred fifty-eight".