18488778 has 48 divisors (see below), whose sum is σ = 46933344. Its totient is φ = 4801440.

The previous prime is 18488777. The next prime is 18488779. The reversal of 18488778 is 87788481.

It is an interprime number because it is at equal distance from previous prime (18488777) and next prime (18488779).

It is a self number, because there is not a number n which added to its sum of digits gives 18488778.

It is not an unprimeable number, because it can be changed into a prime (18488777) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 376 + ... + 6092.

It is an arithmetic number, because the mean of its divisors is an integer number (977778).

Almost surely, 2^18488778 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 18488778, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (23466672).

18488778 is an abundant number, since it is smaller than the sum of its proper divisors (28444566).

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

18488778 is a wasteful number, since it uses less digits than its factorization.

18488778 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5747 (or 5740 counting only the distinct ones).

The product of its digits is 802816, while the sum is 51.

The square root of 18488778 is about 4299.8579046289. The cubic root of 18488778 is about 264.4251357169.

The spelling of 18488778 in words is "eighteen million, four hundred eighty-eight thousand, seven hundred seventy-eight".