856666552249 has 8 divisors (see below), whose sum is σ = 856967068160. Its totient is φ = 856366099056.

The previous prime is 856666552229. The next prime is 856666552283. The reversal of 856666552249 is 942255666658.

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

It is a 3-Lehmer number, since φ(856666552249) divides (856666552249-1)³.

It is a cyclic number.

It is a Carmichael number.

It is not a de Polignac number, because 856666552249 - 2⁷ = 856666552121 is a prime.

It is a deceptive number, since it divides R_856666552248.

It is not an unprimeable number, because it can be changed into a prime (856666552229) by changing a digit.

It is a Zeisel number, with parameters (1, 5226).

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 54629992 + ... + 54645670.

It is an arithmetic number, because the mean of its divisors is an integer number (107120883520).

It is a Poulet number, since it divides 2^856666552248-1.

Almost surely, 2^856666552249 is an apocalyptic number.

It is an amenable number.

856666552249 is a deficient number, since it is larger than the sum of its proper divisors (300515911).

856666552249 is a wasteful number, since it uses less digits than its factorization.

856666552249 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 31359.

The product of its digits is 186624000, while the sum is 64.

The spelling of 856666552249 in words is "eight hundred fifty-six billion, six hundred sixty-six million, five hundred fifty-two thousand, two hundred forty-nine".