218728980 has 36 divisors (see below), whose sum is σ = 663478452. Its totient is φ = 58327680.

The previous prime is 218728967. The next prime is 218729033. The reversal of 218728980 is 89827812.

It is a happy number.

It can be written as a sum of positive squares in 2 ways, for example, as 130782096 + 87946884 = 11436^2 + 9378^2 .

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 an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 607401 + ... + 607760.

It is an arithmetic number, because the mean of its divisors is an integer number (18429957).

Almost surely, 2^218728980 is an apocalyptic number.

218728980 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

218728980 is an abundant number, since it is smaller than the sum of its proper divisors (444749472).

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

218728980 is a wasteful number, since it uses less digits than its factorization.

218728980 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1215176 (or 1215171 counting only the distinct ones).

The product of its (nonzero) digits is 129024, while the sum is 45.

The square root of 218728980 is about 14789.4888349801. The cubic root of 218728980 is about 602.5162659245.

The spelling of 218728980 in words is "two hundred eighteen million, seven hundred twenty-eight thousand, nine hundred eighty".