866655612 has 54 divisors (see below), whose sum is σ = 2274924288. Its totient is φ = 288876456.

The previous prime is 866655611. The next prime is 866655613. The reversal of 866655612 is 216556668.

It is a happy number.

It is an interprime number because it is at equal distance from previous prime (866655611) and next prime (866655613).

It is a tau number, because it is divible by the number of its divisors (54).

It is a super-2 number, since 2×866655612² = 1502183899622189088, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (866655611) by changing a digit.

It is a polite number, since it can be written in 17 ways as a sum of consecutive naturals, for example, 9733 + ... + 42755.

Almost surely, 2^866655612 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 866655612, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1137462144).

866655612 is an abundant number, since it is smaller than the sum of its proper divisors (1408268676).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

866655612 is an equidigital number, since it uses as much as digits as its factorization.

866655612 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 33051 (or 33028 counting only the distinct ones).

The product of its digits is 518400, while the sum is 45.

The square root of 866655612 is about 29439.0151329830. The cubic root of 866655612 is about 953.4154482330.

The spelling of 866655612 in words is "eight hundred sixty-six million, six hundred fifty-five thousand, six hundred twelve".