18783481 has 4 divisors (see below), whose sum is σ = 19009872. Its totient is φ = 18557092.

The previous prime is 18783473. The next prime is 18783491. The reversal of 18783481 is 18438781.

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: 18438781 = 1087 ⋅16963.

It is a cyclic number.

It is not a de Polignac number, because 18783481 - 2³ = 18783473 is a prime.

It is a super-2 number, since 2×18783481² = 705638316954722, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (18783421) 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, 113071 + ... + 113236.

It is an arithmetic number, because the mean of its divisors is an integer number (4752468).

Almost surely, 2^18783481 is an apocalyptic number.

It is an amenable number.

18783481 is a deficient number, since it is larger than the sum of its proper divisors (226391).

18783481 is an equidigital number, since it uses as much as digits as its factorization.

18783481 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 226390.

The product of its digits is 43008, while the sum is 40.

The square root of 18783481 is about 4333.9913474764. The cubic root of 18783481 is about 265.8226765861.

The spelling of 18783481 in words is "eighteen million, seven hundred eighty-three thousand, four hundred eighty-one".