866736989 has 2 divisors, whose sum is σ = 866736990. Its totient is φ = 866736988.

The previous prime is 866736971. The next prime is 866737009. The reversal of 866736989 is 989637668.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 860952964 + 5784025 = 29342^2 + 2405^2 .

It is a cyclic number.

It is not a de Polignac number, because 866736989 - 2²⁰ = 865688413 is a prime.

It is a super-2 number, since 2×866736989² = 1502466016201572242, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (866736929) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 433368494 + 433368495.

It is an arithmetic number, because the mean of its divisors is an integer number (433368495).

Almost surely, 2^866736989 is an apocalyptic number.

It is an amenable number.

866736989 is a deficient number, since it is larger than the sum of its proper divisors (1).

866736989 is an equidigital number, since it uses as much as digits as its factorization.

866736989 is an evil number, because the sum of its binary digits is even.

The product of its digits is 23514624, while the sum is 62.

The square root of 866736989 is about 29440.3972289777. The cubic root of 866736989 is about 953.4452884831.

The spelling of 866736989 in words is "eight hundred sixty-six million, seven hundred thirty-six thousand, nine hundred eighty-nine".