21749548 has 6 divisors (see below), whose sum is σ = 38061716. Its totient is φ = 10874772.

The previous prime is 21749531. The next prime is 21749549. The reversal of 21749548 is 84594712.

It is a self number, because there is not a number n which added to its sum of digits gives 21749548.

It is not an unprimeable number, because it can be changed into a prime (21749549) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 2718690 + ... + 2718697.

Almost surely, 2^21749548 is an apocalyptic number.

It is an amenable number.

21749548 is a deficient number, since it is larger than the sum of its proper divisors (16312168).

21749548 is a wasteful number, since it uses less digits than its factorization.

21749548 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5437391 (or 5437389 counting only the distinct ones).

The product of its digits is 80640, while the sum is 40.

The square root of 21749548 is about 4663.6410668061. The cubic root of 21749548 is about 279.1365749204.

The spelling of 21749548 in words is "twenty-one million, seven hundred forty-nine thousand, five hundred forty-eight".