90218000 has 80 divisors (see below), whose sum is σ = 221295360. Its totient is φ = 35568000.

The previous prime is 90217993. The next prime is 90218033. The reversal of 90218000 is 81209.

It is a tau number, because it is divible by the number of its divisors (80).

It is a Harshad number since it is a multiple of its sum of digits (20).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 157715 + ... + 158285.

It is an arithmetic number, because the mean of its divisors is an integer number (2766192).

Almost surely, 2^90218000 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 90218000, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (110647680).

90218000 is an abundant number, since it is smaller than the sum of its proper divisors (131077360).

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

90218000 is a wasteful number, since it uses less digits than its factorization.

90218000 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 673 (or 657 counting only the distinct ones).

The product of its (nonzero) digits is 144, while the sum is 20.

The square root of 90218000 is about 9498.3156401543. The cubic root of 90218000 is about 448.5020148412.

Adding to 90218000 its reverse (81209), we get a palindrome (90299209).

The spelling of 90218000 in words is "ninety million, two hundred eighteen thousand".