18981856 has 12 divisors (see below), whose sum is σ = 37370592. Its totient is φ = 9490912.

The previous prime is 18981847. The next prime is 18981871. The reversal of 18981856 is 65818981.

It is an alternating number because its digits alternate between odd and even.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 296560 + ... + 296623.

It is an arithmetic number, because the mean of its divisors is an integer number (3114216).

Almost surely, 2^18981856 is an apocalyptic number.

18981856 is a gapful number since it is divisible by the number (16) formed by its first and last digit.

It is an amenable number.

18981856 is a deficient number, since it is larger than the sum of its proper divisors (18388736).

18981856 is an equidigital number, since it uses as much as digits as its factorization.

18981856 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 593193 (or 593185 counting only the distinct ones).

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

The square root of 18981856 is about 4356.8171868923. The cubic root of 18981856 is about 266.7551983825.

The spelling of 18981856 in words is "eighteen million, nine hundred eighty-one thousand, eight hundred fifty-six".