521217172 has 24 divisors (see below), whose sum is σ = 1043078400. Its totient is φ = 223240800.

The previous prime is 521217163. The next prime is 521217173. The reversal of 521217172 is 271712125.

It is a Harshad number since it is a multiple of its sum of digits (28).

It is a self number, because there is not a number n which added to its sum of digits gives 521217172.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (521217173) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 49797 + ... + 59347.

It is an arithmetic number, because the mean of its divisors is an integer number (43461600).

Almost surely, 2^521217172 is an apocalyptic number.

It is an amenable number.

521217172 is an abundant number, since it is smaller than the sum of its proper divisors (521861228).

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

521217172 is a wasteful number, since it uses less digits than its factorization.

521217172 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 11511 (or 11509 counting only the distinct ones).

The product of its digits is 1960, while the sum is 28.

The square root of 521217172 is about 22830.1811644148. The cubic root of 521217172 is about 804.7720877883.

Adding to 521217172 its reverse (271712125), we get a palindrome (792929297).

The spelling of 521217172 in words is "five hundred twenty-one million, two hundred seventeen thousand, one hundred seventy-two".