18980640 has 216 divisors, whose sum is σ = 75626460. Its totient is φ = 4322304.

The previous prime is 18980629. The next prime is 18980659. The reversal of 18980640 is 4608981.

It is a happy number.

18980640 is a `hidden beast` number, since 1 + 8 + 9 + 8 + 0 + 640 = 666.

It can be written as a sum of positive squares in 2 ways, for example, as 16941456 + 2039184 = 4116^2 + 1428^2 .

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

It is a junction number, because it is equal to n+sod(n) for n = 18980595 and 18980604.

It is an unprimeable number.

It is a polite number, since it can be written in 35 ways as a sum of consecutive naturals, for example, 70426 + ... + 70694.

Almost surely, 2^18980640 is an apocalyptic number.

18980640 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 18980640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (37813230).

18980640 is an abundant number, since it is smaller than the sum of its proper divisors (56645820).

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

18980640 is a wasteful number, since it uses less digits than its factorization.

18980640 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 304 (or 286 counting only the distinct ones).

The product of its (nonzero) digits is 13824, while the sum is 36.

The square root of 18980640 is about 4356.6776332430. The cubic root of 18980640 is about 266.7495020437.

The spelling of 18980640 in words is "eighteen million, nine hundred eighty thousand, six hundred forty".