866388069 has 28 divisors (see below), whose sum is σ = 1303481196. Its totient is φ = 575595072.

The previous prime is 866388067. The next prime is 866388071. The reversal of 866388069 is 960883668.

It is an interprime number because it is at equal distance from previous prime (866388067) and next prime (866388071).

It can be written as a sum of positive squares in 2 ways, for example, as 8191044 + 858197025 = 2862^2 + 29295^2 .

It is not a de Polignac number, because 866388069 - 2¹ = 866388067 is a prime.

It is a super-2 number, since 2×866388069² = 1501256572211097522, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (866388067) by changing a digit.

It is a polite number, since it can be written in 27 ways as a sum of consecutive naturals, for example, 226279 + ... + 230075.

Almost surely, 2^866388069 is an apocalyptic number.

It is an amenable number.

866388069 is a deficient number, since it is larger than the sum of its proper divisors (437093127).

866388069 is an equidigital number, since it uses as much as digits as its factorization.

866388069 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4128 (or 4113 counting only the distinct ones).

The product of its (nonzero) digits is 2985984, while the sum is 54.

The square root of 866388069 is about 29434.4707613370. The cubic root of 866388069 is about 953.3173293345.

The spelling of 866388069 in words is "eight hundred sixty-six million, three hundred eighty-eight thousand, sixty-nine".