215820450 has 168 divisors, whose sum is σ = 624531456. Its totient is φ = 55404000.

The previous prime is 215820439. The next prime is 215820463. The reversal of 215820450 is 54028512.

It is a happy number.

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

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 83 ways as a sum of consecutive naturals, for example, 1129855 + ... + 1130045.

Almost surely, 2^215820450 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 215820450, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (312265728).

215820450 is an abundant number, since it is smaller than the sum of its proper divisors (408711006).

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

215820450 is a wasteful number, since it uses less digits than its factorization.

215820450 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 252 (or 232 counting only the distinct ones).

The product of its (nonzero) digits is 3200, while the sum is 27.

The square root of 215820450 is about 14690.8287717201. The cubic root of 215820450 is about 599.8337039136.

Adding to 215820450 its reverse (54028512), we get a palindrome (269848962).

The spelling of 215820450 in words is "two hundred fifteen million, eight hundred twenty thousand, four hundred fifty".