8613603721 has 2 divisors, whose sum is σ = 8613603722. Its totient is φ = 8613603720.

The previous prime is 8613603701. The next prime is 8613603743. The reversal of 8613603721 is 1273063168.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 4945605625 + 3667998096 = 70325^2 + 60564^2 .

It is a cyclic number.

It is not a de Polignac number, because 8613603721 - 2²¹ = 8611506569 is a prime.

It is not a weakly prime, because it can be changed into another prime (8613603701) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 4306801860 + 4306801861.

It is an arithmetic number, because the mean of its divisors is an integer number (4306801861).

Almost surely, 2^8613603721 is an apocalyptic number.

It is an amenable number.

8613603721 is a deficient number, since it is larger than the sum of its proper divisors (1).

8613603721 is an equidigital number, since it uses as much as digits as its factorization.

8613603721 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 36288, while the sum is 37.

The square root of 8613603721 is about 92809.5023206137. The cubic root of 8613603721 is about 2049.8793282925.

Adding to 8613603721 its reverse (1273063168), we get a palindrome (9886666889).

The spelling of 8613603721 in words is "eight billion, six hundred thirteen million, six hundred three thousand, seven hundred twenty-one".