866855406 has 8 divisors (see below), whose sum is σ = 1733710824. Its totient is φ = 288951800.

The previous prime is 866855399. The next prime is 866855413. The reversal of 866855406 is 604558668.

It is a happy number.

It is an interprime number because it is at equal distance from previous prime (866855399) and next prime (866855413).

It is a sphenic number, since it is the product of 3 distinct primes.

866855406 is an admirable number.

It is a super-2 number, since 2×866855406² = 1502876589822849672, which contains 22 as substring.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 72237945 + ... + 72237956.

It is an arithmetic number, because the mean of its divisors is an integer number (216713853).

Almost surely, 2^866855406 is an apocalyptic number.

866855406 is a primitive abundant number, since it is smaller than the sum of its proper divisors, none of which is abundant.

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

866855406 is a wasteful number, since it uses less digits than its factorization.

866855406 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 144475906.

The product of its (nonzero) digits is 1382400, while the sum is 48.

The square root of 866855406 is about 29442.4082914425. The cubic root of 866855406 is about 953.4887076483.

The spelling of 866855406 in words is "eight hundred sixty-six million, eight hundred fifty-five thousand, four hundred six".