215631402 has 64 divisors (see below), whose sum is σ = 503967744. Its totient is φ = 60238080.

The previous prime is 215631397. The next prime is 215631413. The reversal of 215631402 is 204136512.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 497778 + ... + 498210.

It is an arithmetic number, because the mean of its divisors is an integer number (7874496).

Almost surely, 2^215631402 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 215631402, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (251983872).

215631402 is an abundant number, since it is smaller than the sum of its proper divisors (288336342).

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

215631402 is a wasteful number, since it uses less digits than its factorization.

215631402 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 683.

The product of its (nonzero) digits is 1440, while the sum is 24.

The square root of 215631402 is about 14684.3931437428. The cubic root of 215631402 is about 599.6585112348.

Adding to 215631402 its reverse (204136512), we get a palindrome (419767914).

The spelling of 215631402 in words is "two hundred fifteen million, six hundred thirty-one thousand, four hundred two".