8661557747 has 2 divisors, whose sum is σ = 8661557748. Its totient is φ = 8661557746.

The previous prime is 8661557699. The next prime is 8661557753. The reversal of 8661557747 is 7477551668.

8661557747 is digitally balanced in base 3, because in such base it contains all the possibile digits an equal number of times.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 8661557747 - 2¹⁴ = 8661541363 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 8661557692 and 8661557701.

It is not a weakly prime, because it can be changed into another prime (8661557777) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 4330778873 + 4330778874.

It is an arithmetic number, because the mean of its divisors is an integer number (4330778874).

Almost surely, 2^8661557747 is an apocalyptic number.

8661557747 is a deficient number, since it is larger than the sum of its proper divisors (1).

8661557747 is an equidigital number, since it uses as much as digits as its factorization.

8661557747 is an evil number, because the sum of its binary digits is even.

The product of its digits is 9878400, while the sum is 56.

The square root of 8661557747 is about 93067.4902799039. The cubic root of 8661557747 is about 2053.6763495304.

The spelling of 8661557747 in words is "eight billion, six hundred sixty-one million, five hundred fifty-seven thousand, seven hundred forty-seven".