215121330 has 48 divisors (see below), whose sum is σ = 574440984. Its totient is φ = 55814400.

The previous prime is 215121311. The next prime is 215121331. The reversal of 215121330 is 33121512.

215121330 is a `hidden beast` number, since 21 + 512 + 133 + 0 = 666.

It can be written as a sum of positive squares in 4 ways, for example, as 215120889 + 441 = 14667^2 + 21^2 .

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

It is not an unprimeable number, because it can be changed into a prime (215121331) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 28971 + ... + 35630.

Almost surely, 2^215121330 is an apocalyptic number.

215121330 is an abundant number, since it is smaller than the sum of its proper divisors (359319654).

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

215121330 is a wasteful number, since it uses less digits than its factorization.

215121330 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 64651 (or 64648 counting only the distinct ones).

The product of its (nonzero) digits is 180, while the sum is 18.

The square root of 215121330 is about 14667.0150337415. The cubic root of 215121330 is about 599.1853109703.

Adding to 215121330 its reverse (33121512), we get a palindrome (248242842).

The spelling of 215121330 in words is "two hundred fifteen million, one hundred twenty-one thousand, three hundred thirty".