18909774 has 96 divisors (see below), whose sum is σ = 47515104. Its totient is φ = 5598720.

The previous prime is 18909773. The next prime is 18909791. The reversal of 18909774 is 47790981.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (18909773) by changing a digit.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 259002 + ... + 259074.

It is an arithmetic number, because the mean of its divisors is an integer number (494949).

Almost surely, 2^18909774 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 18909774, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (23757552).

18909774 is an abundant number, since it is smaller than the sum of its proper divisors (28605330).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

18909774 is a wasteful number, since it uses less digits than its factorization.

18909774 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 144 (or 132 counting only the distinct ones).

The product of its (nonzero) digits is 127008, while the sum is 45.

The square root of 18909774 is about 4348.5369953583. The cubic root of 18909774 is about 266.4171099310.

It can be divided in two parts, 1890977 and 4, that added together give a palindrome (1890981).

The spelling of 18909774 in words is "eighteen million, nine hundred nine thousand, seven hundred seventy-four".