215640000 has 210 divisors, whose sum is σ = 773658600. Its totient is φ = 57408000.

The previous prime is 215639953. The next prime is 215640011. The reversal of 215640000 is 46512.

It is a happy number.

215640000 is a `hidden beast` number, since 21 + 5 + 640 + 0 + 0 + 0 = 666.

215640000 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a Harshad number since it is a multiple of its sum of digits (18).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 29 ways as a sum of consecutive naturals, for example, 359701 + ... + 360299.

Almost surely, 2^215640000 is an apocalyptic number.

215640000 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 215640000, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (386829300).

215640000 is an abundant number, since it is smaller than the sum of its proper divisors (558018600).

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

215640000 is an equidigital number, since it uses as much as digits as its factorization.

215640000 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 637 (or 609 counting only the distinct ones).

The product of its (nonzero) digits is 240, while the sum is 18.

The square root of 215640000 is about 14684.6859006245. The cubic root of 215640000 is about 599.6664813098. Note that the first 3 decimals are identical.

Adding to 215640000 its reverse (46512), we get a palindrome (215686512).

The spelling of 215640000 in words is "two hundred fifteen million, six hundred forty thousand".