218497890 has 64 divisors (see below), whose sum is σ = 584236800. Its totient is φ = 51926784.

The previous prime is 218497883. The next prime is 218497901. The reversal of 218497890 is 98794812.

It is a Smith number, since the sum of its digits (48) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a Curzon number.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 1651 + ... + 20969.

It is an arithmetic number, because the mean of its divisors is an integer number (9128700).

Almost surely, 2^218497890 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 218497890, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (292118400).

218497890 is an abundant number, since it is smaller than the sum of its proper divisors (365738910).

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

218497890 is a wasteful number, since it uses less digits than its factorization.

218497890 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 19371.

The product of its (nonzero) digits is 290304, while the sum is 48.

The square root of 218497890 is about 14781.6741271075. The cubic root of 218497890 is about 602.3040024080.

The spelling of 218497890 in words is "two hundred eighteen million, four hundred ninety-seven thousand, eight hundred ninety".