215171138 has 48 divisors (see below), whose sum is σ = 402307200. Its totient is φ = 84509568.

The previous prime is 215171137. The next prime is 215171153. The reversal of 215171138 is 831171512.

It is a Curzon number.

It is a self number, because there is not a number n which added to its sum of digits gives 215171138.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (215171137) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 470606 + ... + 471062.

It is an arithmetic number, because the mean of its divisors is an integer number (8381400).

Almost surely, 2^215171138 is an apocalyptic number.

215171138 is a deficient number, since it is larger than the sum of its proper divisors (187136062).

215171138 is a wasteful number, since it uses less digits than its factorization.

215171138 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 691 (or 678 counting only the distinct ones).

The product of its digits is 1680, while the sum is 29.

The square root of 215171138 is about 14668.7128951384. The cubic root of 215171138 is about 599.2315514166.

The spelling of 215171138 in words is "two hundred fifteen million, one hundred seventy-one thousand, one hundred thirty-eight".