21191532 has 24 divisors (see below), whose sum is σ = 49560000. Its totient is φ = 7047696.

The previous prime is 21191531. The next prime is 21191539. The reversal of 21191532 is 23519112.

It is not an unprimeable number, because it can be changed into a prime (21191531) 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, 4219 + ... + 7757.

It is an arithmetic number, because the mean of its divisors is an integer number (2065000).

Almost surely, 2^21191532 is an apocalyptic number.

It is an amenable number.

21191532 is an abundant number, since it is smaller than the sum of its proper divisors (28368468).

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

21191532 is a wasteful number, since it uses less digits than its factorization.

21191532 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4045 (or 4043 counting only the distinct ones).

The product of its digits is 540, while the sum is 24.

The square root of 21191532 is about 4603.4261154058. The cubic root of 21191532 is about 276.7286459746.

The spelling of 21191532 in words is "twenty-one million, one hundred ninety-one thousand, five hundred thirty-two".