53316721 has 2 divisors, whose sum is σ = 53316722. Its totient is φ = 53316720.

The previous prime is 53316719. The next prime is 53316727. The reversal of 53316721 is 12761335.

53316721 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 38192400 + 15124321 = 6180^2 + 3889^2 .

It is a cyclic number.

It is not a de Polignac number, because 53316721 - 2¹ = 53316719 is a prime.

Together with 53316719, it forms a pair of twin primes.

It is a Chen prime.

It is a self number, because there is not a number n which added to its sum of digits gives 53316721.

It is not a weakly prime, because it can be changed into another prime (53316727) 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, 26658360 + 26658361.

It is an arithmetic number, because the mean of its divisors is an integer number (26658361).

Almost surely, 2^53316721 is an apocalyptic number.

It is an amenable number.

53316721 is a deficient number, since it is larger than the sum of its proper divisors (1).

53316721 is an equidigital number, since it uses as much as digits as its factorization.

53316721 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 53316721 is about 7301.8299761087. The cubic root of 53316721 is about 376.3753254835.

The spelling of 53316721 in words is "fifty-three million, three hundred sixteen thousand, seven hundred twenty-one".