18508561980 has 96 divisors (see below), whose sum is σ = 55209579264. Its totient is φ = 4616745984.

The previous prime is 18508561969. The next prime is 18508561987. The reversal of 18508561980 is 8916580581.

It is a Harshad number since it is a multiple of its sum of digits (51).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (18508561987) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 110599 + ... + 221921.

It is an arithmetic number, because the mean of its divisors is an integer number (575099784).

Almost surely, 2^18508561980 is an apocalyptic number.

18508561980 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 18508561980, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (27604789632).

18508561980 is an abundant number, since it is smaller than the sum of its proper divisors (36701017284).

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

18508561980 is a wasteful number, since it uses less digits than its factorization.

18508561980 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 111515 (or 111513 counting only the distinct ones).

The product of its (nonzero) digits is 691200, while the sum is 51.

The spelling of 18508561980 in words is "eighteen billion, five hundred eight million, five hundred sixty-one thousand, nine hundred eighty".