18722401 has 4 divisors (see below), whose sum is σ = 18752704. Its totient is φ = 18692100.

The previous prime is 18722377. The next prime is 18722449. The reversal of 18722401 is 10422781.

It is a happy number.

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, and also an emirpimes, since its reverse is a distinct semiprime: 10422781 = 113 ⋅92237.

It is a cyclic number.

It is not a de Polignac number, because 18722401 - 2⁷ = 18722273 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (18722461) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 14205 + ... + 15466.

It is an arithmetic number, because the mean of its divisors is an integer number (4688176).

Almost surely, 2^18722401 is an apocalyptic number.

It is an amenable number.

18722401 is a deficient number, since it is larger than the sum of its proper divisors (30303).

18722401 is an equidigital number, since it uses as much as digits as its factorization.

18722401 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 30302.

The product of its (nonzero) digits is 896, while the sum is 25.

The square root of 18722401 is about 4326.9389873212. The cubic root of 18722401 is about 265.5342302266.

The spelling of 18722401 in words is "eighteen million, seven hundred twenty-two thousand, four hundred one".