858109491 has 16 divisors (see below), whose sum is σ = 1274752000. Its totient is φ = 570507624.

The previous prime is 858109477. The next prime is 858109519. The reversal of 858109491 is 194901858.

858109491 is a `hidden beast` number, since 8 + 58 + 109 + 491 = 666.

It is not a de Polignac number, because 858109491 - 2¹⁰ = 858108467 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (858109451) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 33391 + ... + 53208.

It is an arithmetic number, because the mean of its divisors is an integer number (79672000).

Almost surely, 2^858109491 is an apocalyptic number.

858109491 is a deficient number, since it is larger than the sum of its proper divisors (416642509).

858109491 is a wasteful number, since it uses less digits than its factorization.

858109491 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 86975 (or 86969 counting only the distinct ones).

The product of its (nonzero) digits is 103680, while the sum is 45.

The square root of 858109491 is about 29293.5059526851. The cubic root of 858109491 is about 950.2712027184.

The spelling of 858109491 in words is "eight hundred fifty-eight million, one hundred nine thousand, four hundred ninety-one".