218900640 has 288 divisors, whose sum is σ = 825297984. Its totient is φ = 48599040.

The previous prime is 218900611. The next prime is 218900651. The reversal of 218900640 is 46009812.

It is a Harshad number since it is a multiple of its sum of digits (30).

It is a junction number, because it is equal to n+sod(n) for n = 218900598 and 218900607.

It is an unprimeable number.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 964207 + ... + 964433.

It is an arithmetic number, because the mean of its divisors is an integer number (2865618).

Almost surely, 2^218900640 is an apocalyptic number.

218900640 is a gapful number since it is divisible by the number (20) 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 218900640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (412648992).

218900640 is an abundant number, since it is smaller than the sum of its proper divisors (606397344).

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

218900640 is a wasteful number, since it uses less digits than its factorization.

218900640 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 300 (or 285 counting only the distinct ones).

The product of its (nonzero) digits is 3456, while the sum is 30.

The square root of 218900640 is about 14795.2911427927. The cubic root of 218900640 is about 602.6738443381.

The spelling of 218900640 in words is "two hundred eighteen million, nine hundred thousand, six hundred forty".