18878401 has 4 divisors (see below), whose sum is σ = 18912852. Its totient is φ = 18843952.

The previous prime is 18878383. The next prime is 18878429. The reversal of 18878401 is 10487881.

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

It can be written as a sum of positive squares in 2 ways, for example, as 7420176 + 11458225 = 2724^2 + 3385^2 .

It is a cyclic number.

It is not a de Polignac number, because 18878401 - 2⁹ = 18877889 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (18878471) 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, 16390 + ... + 17503.

It is an arithmetic number, because the mean of its divisors is an integer number (4728213).

Almost surely, 2^18878401 is an apocalyptic number.

It is an amenable number.

18878401 is a deficient number, since it is larger than the sum of its proper divisors (34451).

18878401 is an equidigital number, since it uses as much as digits as its factorization.

18878401 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 34450.

The product of its (nonzero) digits is 14336, while the sum is 37.

The square root of 18878401 is about 4344.9281927323. The cubic root of 18878401 is about 266.2696917996.

The spelling of 18878401 in words is "eighteen million, eight hundred seventy-eight thousand, four hundred one".