18920001 has 4 divisors (see below), whose sum is σ = 25226672. Its totient is φ = 12613332.

The previous prime is 18919981. The next prime is 18920003. The reversal of 18920001 is 10002981.

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 not a de Polignac number, because 18920001 - 2⁵ = 18919969 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 18920001.

It is not an unprimeable number, because it can be changed into a prime (18920003) 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, 3153331 + ... + 3153336.

It is an arithmetic number, because the mean of its divisors is an integer number (6306668).

Almost surely, 2^18920001 is an apocalyptic number.

It is an amenable number.

18920001 is a deficient number, since it is larger than the sum of its proper divisors (6306671).

18920001 is an equidigital number, since it uses as much as digits as its factorization.

18920001 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6306670.

The product of its (nonzero) digits is 144, while the sum is 21.

The square root of 18920001 is about 4349.7127491364. The cubic root of 18920001 is about 266.4651301901.

Adding to 18920001 its reverse (10002981), we get a palindrome (28922982).

The spelling of 18920001 in words is "eighteen million, nine hundred twenty thousand, one".