8721387061 has 2 divisors, whose sum is σ = 8721387062. Its totient is φ = 8721387060.

The previous prime is 8721387047. The next prime is 8721387071. The reversal of 8721387061 is 1607831278.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 6416811025 + 2304576036 = 80105^2 + 48006^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-8721387061 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 8721386999 and 8721387017.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (8721387071) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 4360693530 + 4360693531.

It is an arithmetic number, because the mean of its divisors is an integer number (4360693531).

Almost surely, 2^8721387061 is an apocalyptic number.

It is an amenable number.

8721387061 is a deficient number, since it is larger than the sum of its proper divisors (1).

8721387061 is an equidigital number, since it uses as much as digits as its factorization.

8721387061 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 112896, while the sum is 43.

The square root of 8721387061 is about 93388.3668397729. The cubic root of 8721387061 is about 2058.3940621719.

The spelling of 8721387061 in words is "eight billion, seven hundred twenty-one million, three hundred eighty-seven thousand, sixty-one".