18655980 has 96 divisors (see below), whose sum is σ = 61146624. Its totient is φ = 4161024.

The previous prime is 18655979. The next prime is 18655981. The reversal of 18655980 is 8955681.

It is an interprime number because it is at equal distance from previous prime (18655979) and next prime (18655981).

It is a Harshad number since it is a multiple of its sum of digits (42).

It is not an unprimeable number, because it can be changed into a prime (18655981) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 17544 + ... + 18576.

It is an arithmetic number, because the mean of its divisors is an integer number (636944).

Almost surely, 2^18655980 is an apocalyptic number.

18655980 is a gapful number since it is divisible by the number (10) 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 18655980, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (30573312).

18655980 is an abundant number, since it is smaller than the sum of its proper divisors (42490644).

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

18655980 is a wasteful number, since it uses less digits than its factorization.

18655980 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1095 (or 1093 counting only the distinct ones).

The product of its (nonzero) digits is 86400, while the sum is 42.

The square root of 18655980 is about 4319.2568805293. The cubic root of 18655980 is about 265.2198484129.

The spelling of 18655980 in words is "eighteen million, six hundred fifty-five thousand, nine hundred eighty".