18782981 has 16 divisors (see below), whose sum is σ = 22554240. Its totient is φ = 15301440.

The previous prime is 18782957. The next prime is 18782999. The reversal of 18782981 is 18928781.

It is not a de Polignac number, because 18782981 - 2⁶ = 18782917 is a prime.

It is a super-2 number, since 2×18782981² = 705600750492722, which contains 22 as substring.

It is a Smith number, since the sum of its digits (44) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (18782921) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 12911 + ... + 14291.

It is an arithmetic number, because the mean of its divisors is an integer number (1409640).

Almost surely, 2^18782981 is an apocalyptic number.

It is an amenable number.

18782981 is a deficient number, since it is larger than the sum of its proper divisors (3771259).

18782981 is a wasteful number, since it uses less digits than its factorization.

18782981 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1484.

The product of its digits is 64512, while the sum is 44.

The square root of 18782981 is about 4333.9336635440. The cubic root of 18782981 is about 265.8203179087.

The spelling of 18782981 in words is "eighteen million, seven hundred eighty-two thousand, nine hundred eighty-one".