215505090 has 128 divisors (see below), whose sum is σ = 629856000. Its totient is φ = 52190208.

The previous prime is 215505077. The next prime is 215505133. The reversal of 215505090 is 90505512.

215505090 is a `hidden beast` number, since 2 + 155 + 0 + 509 + 0 = 666.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is an unprimeable number.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 132301 + ... + 133919.

It is an arithmetic number, because the mean of its divisors is an integer number (4920750).

Almost surely, 2^215505090 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 215505090, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (314928000).

215505090 is an abundant number, since it is smaller than the sum of its proper divisors (414350910).

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

215505090 is a wasteful number, since it uses less digits than its factorization.

215505090 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1681 (or 1675 counting only the distinct ones).

The product of its (nonzero) digits is 2250, while the sum is 27.

The square root of 215505090 is about 14680.0916209675. The cubic root of 215505090 is about 599.5413995654.

The spelling of 215505090 in words is "two hundred fifteen million, five hundred five thousand, ninety".