18811001 has 4 divisors (see below), whose sum is σ = 20521104. Its totient is φ = 17100900.

The previous prime is 18810989. The next prime is 18811021. The reversal of 18811001 is 10011881.

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: 10011881 = 11 ⋅910171.

It is a cyclic number.

It is not a de Polignac number, because 18811001 - 2¹⁰ = 18809977 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (18811021) 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, 855035 + ... + 855056.

It is an arithmetic number, because the mean of its divisors is an integer number (5130276).

Almost surely, 2^18811001 is an apocalyptic number.

18811001 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

It is an amenable number.

18811001 is a deficient number, since it is larger than the sum of its proper divisors (1710103).

18811001 is a wasteful number, since it uses less digits than its factorization.

18811001 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1710102.

The product of its (nonzero) digits is 64, while the sum is 20.

The square root of 18811001 is about 4337.1650879347. The cubic root of 18811001 is about 265.9524336904.

Adding to 18811001 its reverse (10011881), we get a palindrome (28822882).

It can be divided in two parts, 1881 and 1001, that multiplied together give a palindrome (1882881).

The spelling of 18811001 in words is "eighteen million, eight hundred eleven thousand, one".