215551530 has 80 divisors (see below), whose sum is σ = 590647464. Its totient is φ = 56384640.

The previous prime is 215551489. The next prime is 215551543. The reversal of 215551530 is 35155512.

It can be written as a sum of positive squares in 4 ways, for example, as 212838921 + 2712609 = 14589^2 + 1647^2 .

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

It is a junction number, because it is equal to n+sod(n) for n = 215551494 and 215551503.

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 39 ways as a sum of consecutive naturals, for example, 40420 + ... + 45440.

Almost surely, 2^215551530 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 215551530, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (295323732).

215551530 is an abundant number, since it is smaller than the sum of its proper divisors (375095934).

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

215551530 is a wasteful number, since it uses less digits than its factorization.

215551530 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5093 (or 5084 counting only the distinct ones).

The product of its (nonzero) digits is 3750, while the sum is 27.

The square root of 215551530 is about 14681.6732697605. The cubic root of 215551530 is about 599.5844622804.

The spelling of 215551530 in words is "two hundred fifteen million, five hundred fifty-one thousand, five hundred thirty".