18400427 has 4 divisors (see below), whose sum is σ = 18495960. Its totient is φ = 18304896.

The previous prime is 18400423. The next prime is 18400439. The reversal of 18400427 is 72400481.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 18400427 - 2² = 18400423 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 18400396 and 18400405.

It is not an unprimeable number, because it can be changed into a prime (18400423) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 47477 + ... + 47862.

It is an arithmetic number, because the mean of its divisors is an integer number (4623990).

Almost surely, 2^18400427 is an apocalyptic number.

18400427 is a deficient number, since it is larger than the sum of its proper divisors (95533).

18400427 is an equidigital number, since it uses as much as digits as its factorization.

18400427 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 95532.

The product of its (nonzero) digits is 1792, while the sum is 26.

The square root of 18400427 is about 4289.5718900608. The cubic root of 18400427 is about 264.0032665268.

The spelling of 18400427 in words is "eighteen million, four hundred thousand, four hundred twenty-seven".