18895681 has 4 divisors (see below), whose sum is σ = 21595072. Its totient is φ = 16196292.

The previous prime is 18895663. The next prime is 18895691. The reversal of 18895681 is 18659881.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also an emirpimes, since its reverse is a distinct semiprime: 18659881 = 19 ⋅982099.

It is not a de Polignac number, because 18895681 - 2⁹ = 18895169 is a prime.

It is a super-2 number, since 2×18895681² = 714093520907522, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (18895621) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1349685 + ... + 1349698.

It is an arithmetic number, because the mean of its divisors is an integer number (5398768).

Almost surely, 2^18895681 is an apocalyptic number.

It is an amenable number.

18895681 is a deficient number, since it is larger than the sum of its proper divisors (2699391).

18895681 is an equidigital number, since it uses as much as digits as its factorization.

18895681 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2699390.

The product of its digits is 138240, while the sum is 46.

The square root of 18895681 is about 4346.9162632837. The cubic root of 18895681 is about 266.3509087263.

The spelling of 18895681 in words is "eighteen million, eight hundred ninety-five thousand, six hundred eighty-one".