73152721 has 2 divisors, whose sum is σ = 73152722. Its totient is φ = 73152720.

The previous prime is 73152713. The next prime is 73152731. The reversal of 73152721 is 12725137.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 60450625 + 12702096 = 7775^2 + 3564^2 .

It is a cyclic number.

It is not a de Polignac number, because 73152721 - 2³ = 73152713 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 73152721.

It is not a weakly prime, because it can be changed into another prime (73152701) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 36576360 + 36576361.

It is an arithmetic number, because the mean of its divisors is an integer number (36576361).

Almost surely, 2^73152721 is an apocalyptic number.

It is an amenable number.

73152721 is a deficient number, since it is larger than the sum of its proper divisors (1).

73152721 is an equidigital number, since it uses as much as digits as its factorization.

73152721 is an evil number, because the sum of its binary digits is even.

The product of its digits is 2940, while the sum is 28.

The square root of 73152721 is about 8552.9363963495. The cubic root of 73152721 is about 418.2251654256.

Adding to 73152721 its reverse (12725137), we get a palindrome (85877858).

The spelling of 73152721 in words is "seventy-three million, one hundred fifty-two thousand, seven hundred twenty-one".