21757048 has 8 divisors (see below), whose sum is σ = 40794480. Its totient is φ = 10878520.

The previous prime is 21757037. The next prime is 21757049. The reversal of 21757048 is 84075712.

It is a happy number.

It is a tau number, because it is divible by the number of its divisors (8).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21757049) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1359808 + ... + 1359823.

It is an arithmetic number, because the mean of its divisors is an integer number (5099310).

Almost surely, 2^21757048 is an apocalyptic number.

It is an amenable number.

21757048 is a deficient number, since it is larger than the sum of its proper divisors (19037432).

21757048 is a wasteful number, since it uses less digits than its factorization.

21757048 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2719637 (or 2719633 counting only the distinct ones).

The product of its (nonzero) digits is 15680, while the sum is 34.

The square root of 21757048 is about 4664.4450902546. The cubic root of 21757048 is about 279.1686565636.

It can be divided in two parts, 2175704 and 8, that added together give a palindrome (2175712).

The spelling of 21757048 in words is "twenty-one million, seven hundred fifty-seven thousand, forty-eight".