18964816 has 40 divisors (see below), whose sum is σ = 40145000. Its totient is φ = 8626176.

The previous prime is 18964789. The next prime is 18964817. The reversal of 18964816 is 61846981.

It can be written as a sum of positive squares in 4 ways, for example, as 646416 + 18318400 = 804^2 + 4280^2 .

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (18964817) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 14560 + ... + 15808.

It is an arithmetic number, because the mean of its divisors is an integer number (1003625).

Almost surely, 2^18964816 is an apocalyptic number.

18964816 is a gapful number since it is divisible by the number (16) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 18964816, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (20072500).

18964816 is an abundant number, since it is smaller than the sum of its proper divisors (21180184).

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

18964816 is a wasteful number, since it uses less digits than its factorization.

18964816 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1343 (or 1337 counting only the distinct ones).

The product of its digits is 82944, while the sum is 43.

The square root of 18964816 is about 4354.8611918177. The cubic root of 18964816 is about 266.6753524949.

The spelling of 18964816 in words is "eighteen million, nine hundred sixty-four thousand, eight hundred sixteen".