21191488 has 28 divisors (see below), whose sum is σ = 42245280. Its totient is φ = 10547072.

The previous prime is 21191473. The next prime is 21191531. The reversal of 21191488 is 88419112.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 16203 + ... + 17461.

It is an arithmetic number, because the mean of its divisors is an integer number (1508760).

Almost surely, 2^21191488 is an apocalyptic number.

It is an amenable number.

21191488 is a deficient number, since it is larger than the sum of its proper divisors (21053792).

21191488 is a wasteful number, since it uses less digits than its factorization.

21191488 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1534 (or 1524 counting only the distinct ones).

The product of its digits is 4608, while the sum is 34.

The square root of 21191488 is about 4603.4213363541. The cubic root of 21191488 is about 276.7284544505.

The spelling of 21191488 in words is "twenty-one million, one hundred ninety-one thousand, four hundred eighty-eight".