8947355581 has 2 divisors, whose sum is σ = 8947355582. Its totient is φ = 8947355580.

The previous prime is 8947355567. The next prime is 8947355597. The reversal of 8947355581 is 1855537498.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 8200208025 + 747147556 = 90555^2 + 27334^2 .

It is a cyclic number.

It is not a de Polignac number, because 8947355581 - 2²⁹ = 8410484669 is a prime.

It is a super-2 number, since 2×8947355581² (a number of 21 digits) contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (8947455581) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 4473677790 + 4473677791.

It is an arithmetic number, because the mean of its divisors is an integer number (4473677791).

Almost surely, 2^8947355581 is an apocalyptic number.

It is an amenable number.

8947355581 is a deficient number, since it is larger than the sum of its proper divisors (1).

8947355581 is an equidigital number, since it uses as much as digits as its factorization.

8947355581 is an evil number, because the sum of its binary digits is even.

The product of its digits is 6048000, while the sum is 55.

The square root of 8947355581 is about 94590.4624209016. The cubic root of 8947355581 is about 2076.0201559176.

The spelling of 8947355581 in words is "eight billion, nine hundred forty-seven million, three hundred fifty-five thousand, five hundred eighty-one".