8891771969 has 2 divisors, whose sum is σ = 8891771970. Its totient is φ = 8891771968.

The previous prime is 8891771947. The next prime is 8891772017. The reversal of 8891771969 is 9691771988.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 7963777600 + 927994369 = 89240^2 + 30463^2 .

It is a cyclic number.

It is not a de Polignac number, because 8891771969 - 2¹⁶ = 8891706433 is a prime.

It is a super-2 number, since 2×8891771969² (a number of 21 digits) contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (8891771909) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 4445885984 + 4445885985.

It is an arithmetic number, because the mean of its divisors is an integer number (4445885985).

Almost surely, 2^8891771969 is an apocalyptic number.

It is an amenable number.

8891771969 is a deficient number, since it is larger than the sum of its proper divisors (1).

8891771969 is an equidigital number, since it uses as much as digits as its factorization.

8891771969 is an evil number, because the sum of its binary digits is even.

The product of its digits is 13716864, while the sum is 65.

The square root of 8891771969 is about 94296.1927598352. The cubic root of 8891771969 is about 2071.7122730993.

The spelling of 8891771969 in words is "eight billion, eight hundred ninety-one million, seven hundred seventy-one thousand, nine hundred sixty-nine".