18643772 has 48 divisors (see below), whose sum is σ = 39395328. Its totient is φ = 7551360.

The previous prime is 18643733. The next prime is 18643783. The reversal of 18643772 is 27734681.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 40568 + ... + 41024.

It is an arithmetic number, because the mean of its divisors is an integer number (820736).

Almost surely, 2^18643772 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 18643772, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (19697664).

18643772 is an abundant number, since it is smaller than the sum of its proper divisors (20751556).

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

18643772 is a wasteful number, since it uses less digits than its factorization.

18643772 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 546 (or 544 counting only the distinct ones).

The product of its digits is 56448, while the sum is 38.

The square root of 18643772 is about 4317.8434432017. The cubic root of 18643772 is about 265.1619847428.

Subtracting 18643772 from its reverse (27734681), we obtain a palindrome (9090909).

The spelling of 18643772 in words is "eighteen million, six hundred forty-three thousand, seven hundred seventy-two".