18899881 has 32 divisors (see below), whose sum is σ = 25804800. Its totient is φ = 13366080.

The previous prime is 18899861. The next prime is 18899897.

18899881 is nontrivially palindromic in base 10.

It is not a de Polignac number, because 18899881 - 2⁵ = 18899849 is a prime.

It is a super-2 number, since 2×18899881² = 714411003628322, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (18899821) 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, 78960 + ... + 79198.

It is an arithmetic number, because the mean of its divisors is an integer number (806400).

Almost surely, 2^18899881 is an apocalyptic number.

18899881 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

It is an amenable number.

18899881 is a deficient number, since it is larger than the sum of its proper divisors (6904919).

18899881 is a wasteful number, since it uses less digits than its factorization.

18899881 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 349.

The product of its digits is 331776, while the sum is 52.

The square root of 18899881 is about 4347.3993375350. The cubic root of 18899881 is about 266.3706414709.

The spelling of 18899881 in words is "eighteen million, eight hundred ninety-nine thousand, eight hundred eighty-one".