72447757 has 2 divisors, whose sum is σ = 72447758. Its totient is φ = 72447756.

The previous prime is 72447737. The next prime is 72447763. The reversal of 72447757 is 75774427.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 37625956 + 34821801 = 6134^2 + 5901^2 .

It is an emirp because it is prime and its reverse (75774427) is a distict prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-72447757 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (72447707) 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, 36223878 + 36223879.

It is an arithmetic number, because the mean of its divisors is an integer number (36223879).

Almost surely, 2^72447757 is an apocalyptic number.

It is an amenable number.

72447757 is a deficient number, since it is larger than the sum of its proper divisors (1).

72447757 is an equidigital number, since it uses as much as digits as its factorization.

72447757 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 384160, while the sum is 43.

The square root of 72447757 is about 8511.6248155097. The cubic root of 72447757 is about 416.8773646551.

The spelling of 72447757 in words is "seventy-two million, four hundred forty-seven thousand, seven hundred fifty-seven".