73116721 has 2 divisors, whose sum is σ = 73116722. Its totient is φ = 73116720.

The previous prime is 73116697. The next prime is 73116737. The reversal of 73116721 is 12761137.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 51624225 + 21492496 = 7185^2 + 4636^2 .

It is a cyclic number.

It is not a de Polignac number, because 73116721 - 2¹¹ = 73114673 is a prime.

It is a nialpdrome in base 15.

It is a self number, because there is not a number n which added to its sum of digits gives 73116721.

It is not a weakly prime, because it can be changed into another prime (73116751) 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, 36558360 + 36558361.

It is an arithmetic number, because the mean of its divisors is an integer number (36558361).

Almost surely, 2^73116721 is an apocalyptic number.

It is an amenable number.

73116721 is a deficient number, since it is larger than the sum of its proper divisors (1).

73116721 is an equidigital number, since it uses as much as digits as its factorization.

73116721 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 1764, while the sum is 28.

The square root of 73116721 is about 8550.8315969852. The cubic root of 73116721 is about 418.1565483542.

Adding to 73116721 its reverse (12761137), we get a palindrome (85877858).

It can be divided in two parts, 73116 and 721, that added together give a palindrome (73837).

The spelling of 73116721 in words is "seventy-three million, one hundred sixteen thousand, seven hundred twenty-one".