215978247 has 12 divisors (see below), whose sum is σ = 317083624. Its totient is φ = 141624720.

The previous prime is 215978239. The next prime is 215978249. The reversal of 215978247 is 742879512.

It is a happy number.

It is not a de Polignac number, because 215978247 - 2³ = 215978239 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (215978249) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 196153 + ... + 197250.

Almost surely, 2^215978247 is an apocalyptic number.

215978247 is a deficient number, since it is larger than the sum of its proper divisors (101105377).

215978247 is a wasteful number, since it uses less digits than its factorization.

215978247 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 393470 (or 393467 counting only the distinct ones).

The product of its digits is 282240, while the sum is 45.

The square root of 215978247 is about 14696.1983859772. The cubic root of 215978247 is about 599.9798576572.

It can be divided in two parts, 215978 and 247, that added together give a square (216225 = 465²).

The spelling of 215978247 in words is "two hundred fifteen million, nine hundred seventy-eight thousand, two hundred forty-seven".