18681865 has 8 divisors (see below), whose sum is σ = 23393088. Its totient is φ = 14295600.

The previous prime is 18681863. The next prime is 18681899. The reversal of 18681865 is 56818681.

It is a happy number.

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

It is not a de Polignac number, because 18681865 - 2¹ = 18681863 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (18681863) 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, 81111 + ... + 81340.

It is an arithmetic number, because the mean of its divisors is an integer number (2924136).

Almost surely, 2^18681865 is an apocalyptic number.

It is an amenable number.

18681865 is a deficient number, since it is larger than the sum of its proper divisors (4711223).

18681865 is a wasteful number, since it uses less digits than its factorization.

18681865 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 162479.

The product of its digits is 92160, while the sum is 43.

The square root of 18681865 is about 4322.2523063792. The cubic root of 18681865 is about 265.3424550888.

The spelling of 18681865 in words is "eighteen million, six hundred eighty-one thousand, eight hundred sixty-five".