866191131 has 32 divisors (see below), whose sum is σ = 1392121920. Its totient is φ = 529120512.

The previous prime is 866191129. The next prime is 866191147. The reversal of 866191131 is 131191668.

It is a happy number.

866191131 is a `hidden beast` number, since 8 + 6 + 619 + 1 + 1 + 31 = 666.

It is not a de Polignac number, because 866191131 - 2¹ = 866191129 is a prime.

It is a super-2 number, since 2×866191131² = 1500574150846118322, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (866191631) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 39081 + ... + 57093.

It is an arithmetic number, because the mean of its divisors is an integer number (43503810).

Almost surely, 2^866191131 is an apocalyptic number.

866191131 is a deficient number, since it is larger than the sum of its proper divisors (525930789).

866191131 is a wasteful number, since it uses less digits than its factorization.

866191131 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 18172 (or 18166 counting only the distinct ones).

The product of its digits is 7776, while the sum is 36.

The square root of 866191131 is about 29431.1252078476. The cubic root of 866191131 is about 953.2450912532.

The spelling of 866191131 in words is "eight hundred sixty-six million, one hundred ninety-one thousand, one hundred thirty-one".