21743737 has 2 divisors, whose sum is σ = 21743738. Its totient is φ = 21743736.

The previous prime is 21743699. The next prime is 21743749. The reversal of 21743737 is 73734712.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 18224361 + 3519376 = 4269^2 + 1876^2 .

It is a cyclic number.

It is not a de Polignac number, because 21743737 - 2¹¹ = 21741689 is a prime.

It is not a weakly prime, because it can be changed into another prime (21743437) 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, 10871868 + 10871869.

It is an arithmetic number, because the mean of its divisors is an integer number (10871869).

Almost surely, 2^21743737 is an apocalyptic number.

It is an amenable number.

21743737 is a deficient number, since it is larger than the sum of its proper divisors (1).

21743737 is an equidigital number, since it uses as much as digits as its factorization.

21743737 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 24696, while the sum is 34.

The square root of 21743737 is about 4663.0180141192. The cubic root of 21743737 is about 279.1117129920. Note that the first 3 decimals are identical.

The spelling of 21743737 in words is "twenty-one million, seven hundred forty-three thousand, seven hundred thirty-seven".