215978382 has 24 divisors (see below), whose sum is σ = 468735696. Its totient is φ = 71872416.

The previous prime is 215978381. The next prime is 215978383. The reversal of 215978382 is 283879512.

It is a happy number.

215978382 is a `hidden beast` number, since 21 + 597 + 8 + 38 + 2 = 666.

It is an interprime number because it is at equal distance from previous prime (215978381) and next prime (215978383).

It is a super-2 number, since 2×215978382² = 93293322982675848, which contains 22 as substring.

It is a congruent number.

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 11 ways as a sum of consecutive naturals, for example, 1383 + ... + 20829.

It is an arithmetic number, because the mean of its divisors is an integer number (19530654).

Almost surely, 2^215978382 is an apocalyptic number.

215978382 is an abundant number, since it is smaller than the sum of its proper divisors (252757314).

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

215978382 is a wasteful number, since it uses less digits than its factorization.

215978382 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 20072 (or 20069 counting only the distinct ones).

The product of its digits is 241920, while the sum is 45.

The square root of 215978382 is about 14696.2029790011. The cubic root of 215978382 is about 599.9799826655.

The spelling of 215978382 in words is "two hundred fifteen million, nine hundred seventy-eight thousand, three hundred eighty-two".