72250721 has 2 divisors, whose sum is σ = 72250722. Its totient is φ = 72250720.

The previous prime is 72250699. The next prime is 72250727. The reversal of 72250721 is 12705227.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 65286400 + 6964321 = 8080^2 + 2639^2 .

It is a cyclic number.

It is not a de Polignac number, because 72250721 - 2¹⁸ = 71988577 is a prime.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (72250727) 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, 36125360 + 36125361.

It is an arithmetic number, because the mean of its divisors is an integer number (36125361).

Almost surely, 2^72250721 is an apocalyptic number.

It is an amenable number.

72250721 is a deficient number, since it is larger than the sum of its proper divisors (1).

72250721 is an equidigital number, since it uses as much as digits as its factorization.

72250721 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 1960, while the sum is 26.

The square root of 72250721 is about 8500.0424116589. The cubic root of 72250721 is about 416.4990947139.

Adding to 72250721 its reverse (12705227), we get a palindrome (84955948).

The spelling of 72250721 in words is "seventy-two million, two hundred fifty thousand, seven hundred twenty-one".