8567997661 has 2 divisors, whose sum is σ = 8567997662. Its totient is φ = 8567997660.

The previous prime is 8567997563. The next prime is 8567997667. The reversal of 8567997661 is 1667997658.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 4346896761 + 4221100900 = 65931^2 + 64970^2 .

It is a cyclic number.

It is not a de Polignac number, because 8567997661 - 2⁹ = 8567997149 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 8567997593 and 8567997602.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (8567997667) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 4283998830 + 4283998831.

It is an arithmetic number, because the mean of its divisors is an integer number (4283998831).

Almost surely, 2^8567997661 is an apocalyptic number.

It is an amenable number.

8567997661 is a deficient number, since it is larger than the sum of its proper divisors (1).

8567997661 is an equidigital number, since it uses as much as digits as its factorization.

8567997661 is an evil number, because the sum of its binary digits is even.

The product of its digits is 34292160, while the sum is 64.

The square root of 8567997661 is about 92563.4790886773. The cubic root of 8567997661 is about 2046.2551231638.

It can be divided in two parts, 8567997 and 661, that added together give a palindrome (8568658).

The spelling of 8567997661 in words is "eight billion, five hundred sixty-seven million, nine hundred ninety-seven thousand, six hundred sixty-one".