18157861 has 8 divisors (see below), whose sum is σ = 18714240. Its totient is φ = 17605008.

The previous prime is 18157859. The next prime is 18157873. The reversal of 18157861 is 16875181.

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

It is a cyclic number.

It is not a de Polignac number, because 18157861 - 2¹ = 18157859 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (37).

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 18157861.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (18157831) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 12600 + ... + 13966.

It is an arithmetic number, because the mean of its divisors is an integer number (2339280).

Almost surely, 2^18157861 is an apocalyptic number.

It is an amenable number.

18157861 is a deficient number, since it is larger than the sum of its proper divisors (556379).

18157861 is a wasteful number, since it uses less digits than its factorization.

18157861 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1763.

The product of its digits is 13440, while the sum is 37.

The square root of 18157861 is about 4261.2041725315. The cubic root of 18157861 is about 262.8380455087.

The spelling of 18157861 in words is "eighteen million, one hundred fifty-seven thousand, eight hundred sixty-one".