161858871 has 32 divisors (see below), whose sum is σ = 244440000. Its totient is φ = 105836544.

The previous prime is 161858867. The next prime is 161858897. The reversal of 161858871 is 178858161.

161858871 is a `hidden beast` number, since 1 + 61 + 8 + 588 + 7 + 1 = 666.

It is not a de Polignac number, because 161858871 - 2² = 161858867 is a prime.

Its product of digits (107520) is a multiple of the sum of its prime factors (640).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (161858821) 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, 463605 + ... + 463953.

It is an arithmetic number, because the mean of its divisors is an integer number (7638750).

Almost surely, 2^161858871 is an apocalyptic number.

161858871 is a deficient number, since it is larger than the sum of its proper divisors (82581129).

161858871 is a wasteful number, since it uses less digits than its factorization.

161858871 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 640 (or 634 counting only the distinct ones).

The product of its digits is 107520, while the sum is 45.

The square root of 161858871 is about 12722.3767826613. The cubic root of 161858871 is about 544.9778303694.

The spelling of 161858871 in words is "one hundred sixty-one million, eight hundred fifty-eight thousand, eight hundred seventy-one".