18400481 has 4 divisors (see below), whose sum is σ = 20073264. Its totient is φ = 16727700.

The previous prime is 18400451. The next prime is 18400489.

18400481 is nontrivially palindromic in base 10.

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 a de Polignac number, because none of the positive numbers 2^k-18400481 is a prime.

It is a super-2 number, since 2×18400481² = 677155402062722, which contains 22 as substring.

It is a Duffinian number.

It is a Curzon number.

It is a self number, because there is not a number n which added to its sum of digits gives 18400481.

It is not an unprimeable number, because it can be changed into a prime (18400489) 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, 836375 + ... + 836396.

It is an arithmetic number, because the mean of its divisors is an integer number (5018316).

Almost surely, 2^18400481 is an apocalyptic number.

18400481 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

It is an amenable number.

18400481 is a deficient number, since it is larger than the sum of its proper divisors (1672783).

18400481 is a wasteful number, since it uses less digits than its factorization.

18400481 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1672782.

The product of its (nonzero) digits is 1024, while the sum is 26.

The square root of 18400481 is about 4289.5781843906. The cubic root of 18400481 is about 264.0035247846.

It can be divided in two parts, 18400 and 481, that added together give a palindrome (18881).

The spelling of 18400481 in words is "eighteen million, four hundred thousand, four hundred eighty-one".