18881481 has 4 divisors (see below), whose sum is σ = 25175312. Its totient is φ = 12587652.

The previous prime is 18881461. The next prime is 18881483. The reversal of 18881481 is 18418881.

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.

It is not a de Polignac number, because 18881481 - 2¹¹ = 18879433 is a prime.

It is a super-2 number, since 2×18881481² = 713020649506722, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (18881483) 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, 3146911 + ... + 3146916.

It is an arithmetic number, because the mean of its divisors is an integer number (6293828).

Almost surely, 2^18881481 is an apocalyptic number.

It is an amenable number.

18881481 is a deficient number, since it is larger than the sum of its proper divisors (6293831).

18881481 is an equidigital number, since it uses as much as digits as its factorization.

18881481 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6293830.

The product of its digits is 16384, while the sum is 39.

The square root of 18881481 is about 4345.2826145143. The cubic root of 18881481 is about 266.2841715933.

The spelling of 18881481 in words is "eighteen million, eight hundred eighty-one thousand, four hundred eighty-one".