215105172 has 12 divisors (see below), whose sum is σ = 501912096. Its totient is φ = 71701720.

The previous prime is 215105167. The next prime is 215105173. The reversal of 215105172 is 271501512.

215105172 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a tau number, because it is divible by the number of its divisors (12).

It is a super-2 number, since 2×215105172² = 92540470042299168, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (215105173) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 8962704 + ... + 8962727.

It is an arithmetic number, because the mean of its divisors is an integer number (41826008).

Almost surely, 2^215105172 is an apocalyptic number.

It is an amenable number.

215105172 is an abundant number, since it is smaller than the sum of its proper divisors (286806924).

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

215105172 is a wasteful number, since it uses less digits than its factorization.

215105172 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 17925438 (or 17925436 counting only the distinct ones).

The product of its (nonzero) digits is 700, while the sum is 24.

The square root of 215105172 is about 14666.4641955722. The cubic root of 215105172 is about 599.1703087718.

Adding to 215105172 its reverse (271501512), we get a palindrome (486606684).

The spelling of 215105172 in words is "two hundred fifteen million, one hundred five thousand, one hundred seventy-two".