18861887 has 8 divisors (see below), whose sum is σ = 20926080. Its totient is φ = 16855960.

The previous prime is 18861881. The next prime is 18861893. The reversal of 18861887 is 78816881.

It is an interprime number because it is at equal distance from previous prime (18861881) and next prime (18861893).

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

It is not a de Polignac number, because 18861887 - 2²⁴ = 2084671 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (18861881) 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, 13883 + ... + 15180.

It is an arithmetic number, because the mean of its divisors is an integer number (2615760).

Almost surely, 2^18861887 is an apocalyptic number.

18861887 is a deficient number, since it is larger than the sum of its proper divisors (2064193).

18861887 is a wasteful number, since it uses less digits than its factorization.

18861887 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 29133.

The product of its digits is 172032, while the sum is 47.

The square root of 18861887 is about 4343.0274003280. The cubic root of 18861887 is about 266.1920287873.

It can be divided in two parts, 1886 and 1887, that added together give a palindrome (3773).

The spelling of 18861887 in words is "eighteen million, eight hundred sixty-one thousand, eight hundred eighty-seven".