21191088 has 40 divisors (see below), whose sum is σ = 56022208. Its totient is φ = 6898752.

The previous prime is 21191081. The next prime is 21191111. The reversal of 21191088 is 88019112.

It is not an unprimeable number, because it can be changed into a prime (21191081) 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 7 ways as a sum of consecutive naturals, for example, 3070 + ... + 7197.

Almost surely, 2^21191088 is an apocalyptic number.

It is an amenable number.

21191088 is an abundant number, since it is smaller than the sum of its proper divisors (34831120).

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

21191088 is a wasteful number, since it uses less digits than its factorization.

21191088 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10321 (or 10315 counting only the distinct ones).

The product of its (nonzero) digits is 1152, while the sum is 30.

The square root of 21191088 is about 4603.3778902019. The cubic root of 21191088 is about 276.7267133099.

The spelling of 21191088 in words is "twenty-one million, one hundred ninety-one thousand, eighty-eight".