73285721 has 2 divisors, whose sum is σ = 73285722. Its totient is φ = 73285720.

The previous prime is 73285711. The next prime is 73285727. The reversal of 73285721 is 12758237.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 71995225 + 1290496 = 8485^2 + 1136^2 .

It is an emirp because it is prime and its reverse (12758237) is a distict prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-73285721 is a prime.

It is not a weakly prime, because it can be changed into another prime (73285727) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 36642860 + 36642861.

It is an arithmetic number, because the mean of its divisors is an integer number (36642861).

Almost surely, 2^73285721 is an apocalyptic number.

It is an amenable number.

73285721 is a deficient number, since it is larger than the sum of its proper divisors (1).

73285721 is an equidigital number, since it uses as much as digits as its factorization.

73285721 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 23520, while the sum is 35.

The square root of 73285721 is about 8560.7079730592. The cubic root of 73285721 is about 418.4784723430.

The spelling of 73285721 in words is "seventy-three million, two hundred eighty-five thousand, seven hundred twenty-one".