72603721 has 2 divisors, whose sum is σ = 72603722. Its totient is φ = 72603720.

The previous prime is 72603703. The next prime is 72603761. The reversal of 72603721 is 12730627.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 52925625 + 19678096 = 7275^2 + 4436^2 .

It is a cyclic number.

It is not a de Polignac number, because 72603721 - 2⁷ = 72603593 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 72603721.

It is not a weakly prime, because it can be changed into another prime (72603761) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 36301860 + 36301861.

It is an arithmetic number, because the mean of its divisors is an integer number (36301861).

Almost surely, 2^72603721 is an apocalyptic number.

It is an amenable number.

72603721 is a deficient number, since it is larger than the sum of its proper divisors (1).

72603721 is an equidigital number, since it uses as much as digits as its factorization.

72603721 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 3528, while the sum is 28.

The square root of 72603721 is about 8520.7817129651. The cubic root of 72603721 is about 417.1762985046.

The spelling of 72603721 in words is "seventy-two million, six hundred three thousand, seven hundred twenty-one".