21753737 has 2 divisors, whose sum is σ = 21753738. Its totient is φ = 21753736.

The previous prime is 21753731. The next prime is 21753749. The reversal of 21753737 is 73735712.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 21752896 + 841 = 4664^2 + 29^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21753737 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 21753697 and 21753706.

It is not a weakly prime, because it can be changed into another prime (21753731) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10876868 + 10876869.

It is an arithmetic number, because the mean of its divisors is an integer number (10876869).

Almost surely, 2^21753737 is an apocalyptic number.

It is an amenable number.

21753737 is a deficient number, since it is larger than the sum of its proper divisors (1).

21753737 is an equidigital number, since it uses as much as digits as its factorization.

21753737 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 30870, while the sum is 35.

The square root of 21753737 is about 4664.0901577907. The cubic root of 21753737 is about 279.1544944966.

The spelling of 21753737 in words is "twenty-one million, seven hundred fifty-three thousand, seven hundred thirty-seven".