215481388 has 12 divisors (see below), whose sum is σ = 393487920. Its totient is φ = 103056272.

The previous prime is 215481367. The next prime is 215481389. The reversal of 215481388 is 883184512.

It is a self number, because there is not a number n which added to its sum of digits gives 215481388.

It is not an unprimeable number, because it can be changed into a prime (215481389) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1171003 + ... + 1171186.

It is an arithmetic number, because the mean of its divisors is an integer number (32790660).

Almost surely, 2^215481388 is an apocalyptic number.

It is an amenable number.

215481388 is a deficient number, since it is larger than the sum of its proper divisors (178006532).

215481388 is a wasteful number, since it uses less digits than its factorization.

215481388 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2342216 (or 2342214 counting only the distinct ones).

The product of its digits is 61440, while the sum is 40.

The square root of 215481388 is about 14679.2843149794. The cubic root of 215481388 is about 599.5194188761.

The spelling of 215481388 in words is "two hundred fifteen million, four hundred eighty-one thousand, three hundred eighty-eight".