21760756 has 6 divisors (see below), whose sum is σ = 38081330. Its totient is φ = 10880376.

The previous prime is 21760751. The next prime is 21760763. The reversal of 21760756 is 65706712.

It can be written as a sum of positive squares in only one way, i.e., 18627856 + 3132900 = 4316^2 + 1770^2 .

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21760751) 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 as a sum of consecutive naturals, namely, 2720091 + ... + 2720098.

Almost surely, 2^21760756 is an apocalyptic number.

It is an amenable number.

21760756 is a deficient number, since it is larger than the sum of its proper divisors (16320574).

21760756 is a wasteful number, since it uses less digits than its factorization.

21760756 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5440193 (or 5440191 counting only the distinct ones).

The product of its (nonzero) digits is 17640, while the sum is 34.

The square root of 21760756 is about 4664.8425482539. The cubic root of 21760756 is about 279.1845150045.

The spelling of 21760756 in words is "twenty-one million, seven hundred sixty thousand, seven hundred fifty-six".