215217240 has 64 divisors (see below), whose sum is σ = 737890560. Its totient is φ = 49192320.

The previous prime is 215217227. The next prime is 215217281. The reversal of 215217240 is 42712512.

It is a Harshad number since it is a multiple of its sum of digits (24).

It is a self number, because there is not a number n which added to its sum of digits gives 215217240.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 127266 + ... + 128945.

It is an arithmetic number, because the mean of its divisors is an integer number (11529540).

Almost surely, 2^215217240 is an apocalyptic number.

215217240 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

215217240 is an abundant number, since it is smaller than the sum of its proper divisors (522673320).

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

215217240 is a wasteful number, since it uses less digits than its factorization.

215217240 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 256232 (or 256228 counting only the distinct ones).

The product of its (nonzero) digits is 1120, while the sum is 24.

The square root of 215217240 is about 14670.2842508249. The cubic root of 215217240 is about 599.2743449506.

Adding to 215217240 its reverse (42712512), we get a palindrome (257929752).

The spelling of 215217240 in words is "two hundred fifteen million, two hundred seventeen thousand, two hundred forty".