18289980 has 36 divisors (see below), whose sum is σ = 55480152. Its totient is φ = 4877280.

The previous prime is 18289979. The next prime is 18289987. The reversal of 18289980 is 8998281.

It is a tau number, because it is divible by the number of its divisors (36).

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

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (18289987) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 50626 + ... + 50985.

Almost surely, 2^18289980 is an apocalyptic number.

18289980 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

18289980 is an abundant number, since it is smaller than the sum of its proper divisors (37190172).

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

18289980 is a wasteful number, since it uses less digits than its factorization.

18289980 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 101626 (or 101621 counting only the distinct ones).

The product of its (nonzero) digits is 82944, while the sum is 45.

The square root of 18289980 is about 4276.6786178061. The cubic root of 18289980 is about 263.4739870646.

The spelling of 18289980 in words is "eighteen million, two hundred eighty-nine thousand, nine hundred eighty".