21316753 has 2 divisors, whose sum is σ = 21316754. Its totient is φ = 21316752.

The previous prime is 21316751. The next prime is 21316783. The reversal of 21316753 is 35761312.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 21316689 + 64 = 4617^2 + 8^2 .

It is a cyclic number.

It is not a de Polignac number, because 21316753 - 2¹ = 21316751 is a prime.

Together with 21316751, it forms a pair of twin primes.

It is equal to p_1348741 and since 21316753 and 1348741 have the same sum of digits, it is a Honaker prime.

It is not a weakly prime, because it can be changed into another prime (21316751) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10658376 + 10658377.

It is an arithmetic number, because the mean of its divisors is an integer number (10658377).

Almost surely, 2^21316753 is an apocalyptic number.

It is an amenable number.

21316753 is a deficient number, since it is larger than the sum of its proper divisors (1).

21316753 is an equidigital number, since it uses as much as digits as its factorization.

21316753 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 3780, while the sum is 28.

The square root of 21316753 is about 4617.0069309023. The cubic root of 21316753 is about 277.2726401114.

The spelling of 21316753 in words is "twenty-one million, three hundred sixteen thousand, seven hundred fifty-three".