18361980 has 288 divisors, whose sum is σ = 73382400. Its totient is φ = 3608064.

The previous prime is 18361979. The next prime is 18361991. The reversal of 18361980 is 8916381.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 95 ways as a sum of consecutive naturals, for example, 311191 + ... + 311249.

It is an arithmetic number, because the mean of its divisors is an integer number (254800).

Almost surely, 2^18361980 is an apocalyptic number.

18361980 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 18361980, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (36691200).

18361980 is an abundant number, since it is smaller than the sum of its proper divisors (55020420).

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

18361980 is a wasteful number, since it uses less digits than its factorization.

18361980 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 113 (or 108 counting only the distinct ones).

The product of its (nonzero) digits is 10368, while the sum is 36.

The square root of 18361980 is about 4285.0880971107. The cubic root of 18361980 is about 263.8192633467.

The spelling of 18361980 in words is "eighteen million, three hundred sixty-one thousand, nine hundred eighty".