21548668 has 6 divisors (see below), whose sum is σ = 37710176. Its totient is φ = 10774332.

The previous prime is 21548621. The next prime is 21548669. The reversal of 21548668 is 86684512.

It is a self number, because there is not a number n which added to its sum of digits gives 21548668.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21548669) 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 as a sum of consecutive naturals, namely, 2693580 + ... + 2693587.

Almost surely, 2^21548668 is an apocalyptic number.

It is an amenable number.

21548668 is a deficient number, since it is larger than the sum of its proper divisors (16161508).

21548668 is a wasteful number, since it uses less digits than its factorization.

21548668 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5387171 (or 5387169 counting only the distinct ones).

The product of its digits is 92160, while the sum is 40.

The square root of 21548668 is about 4642.0542866279. The cubic root of 21548668 is about 278.2745420266.

The spelling of 21548668 in words is "twenty-one million, five hundred forty-eight thousand, six hundred sixty-eight".