215978385 has 32 divisors (see below), whose sum is σ = 395688960. Its totient is φ = 98543808.

The previous prime is 215978383. The next prime is 215978401. The reversal of 215978385 is 583879512.

It is not a de Polignac number, because 215978385 - 2¹ = 215978383 is a prime.

It is not an unprimeable number, because it can be changed into a prime (215978381) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 63334 + ... + 66656.

It is an arithmetic number, because the mean of its divisors is an integer number (12365280).

Almost surely, 2^215978385 is an apocalyptic number.

It is an amenable number.

215978385 is a deficient number, since it is larger than the sum of its proper divisors (179710575).

215978385 is a wasteful number, since it uses less digits than its factorization.

215978385 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3957.

The product of its digits is 604800, while the sum is 48.

The square root of 215978385 is about 14696.2030810683. The cubic root of 215978385 is about 599.9799854435.

The spelling of 215978385 in words is "two hundred fifteen million, nine hundred seventy-eight thousand, three hundred eighty-five".