18955980 has 72 divisors (see below), whose sum is σ = 58614192. Its totient is φ = 4957056.

The previous prime is 18955957. The next prime is 18955987. The reversal of 18955980 is 8955981.

18955980 is a `hidden beast` number, since 18 + 9 + 559 + 80 = 666.

It is a Harshad number since it is a multiple of its sum of digits (45).

It is not an unprimeable number, because it can be changed into a prime (18955987) 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, 8547 + ... + 10533.

It is an arithmetic number, because the mean of its divisors is an integer number (814086).

Almost surely, 2^18955980 is an apocalyptic number.

18955980 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 18955980, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (29307096).

18955980 is an abundant number, since it is smaller than the sum of its proper divisors (39658212).

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

18955980 is a wasteful number, since it uses less digits than its factorization.

18955980 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2055 (or 2050 counting only the distinct ones).

The product of its (nonzero) digits is 129600, while the sum is 45.

The square root of 18955980 is about 4353.8465751563. The cubic root of 18955980 is about 266.6339300091.

Subtracting from 18955980 its reverse (8955981), we obtain a palindrome (9999999).

It can be divided in two parts, 1895 and 5980, that added together give a triangular number (7875 = T₁₂₅).

The spelling of 18955980 in words is "eighteen million, nine hundred fifty-five thousand, nine hundred eighty".