18831081 has 4 divisors (see below), whose sum is σ = 25108112. Its totient is φ = 12554052.

The previous prime is 18831079. The next prime is 18831083. The reversal of 18831081 is 18013881.

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 an interprime number because it is at equal distance from previous prime (18831079) and next prime (18831083).

It is not a de Polignac number, because 18831081 - 2¹ = 18831079 is a prime.

It is a super-2 number, since 2×18831081² = 709219223257122, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (18831083) 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, 3138511 + ... + 3138516.

It is an arithmetic number, because the mean of its divisors is an integer number (6277028).

Almost surely, 2^18831081 is an apocalyptic number.

It is an amenable number.

18831081 is a deficient number, since it is larger than the sum of its proper divisors (6277031).

18831081 is an equidigital number, since it uses as much as digits as its factorization.

18831081 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6277030.

The product of its (nonzero) digits is 1536, while the sum is 30.

The square root of 18831081 is about 4339.4793466498. The cubic root of 18831081 is about 266.0470312754.

The spelling of 18831081 in words is "eighteen million, eight hundred thirty-one thousand, eighty-one".