217313825 has 12 divisors (see below), whose sum is σ = 269766588. Its totient is φ = 173659200.

The previous prime is 217313819. The next prime is 217313827. The reversal of 217313825 is 528313712.

It can be written as a sum of positive squares in 6 ways, for example, as 132802576 + 84511249 = 11524^2 + 9193^2 .

It is not a de Polignac number, because 217313825 - 2⁴ = 217313809 is a prime.

It is a super-2 number, since 2×217313825² = 94450597072261250, which contains 22 as substring.

It is a hoax number, since the sum of its digits (32) coincides with the sum of the digits of its distinct prime factors.

It is a Duffinian number.

It is a Curzon number.

It is a junction number, because it is equal to n+sod(n) for n = 217313791 and 217313800.

It is not an unprimeable number, because it can be changed into a prime (217313827) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 21035 + ... + 29615.

It is an arithmetic number, because the mean of its divisors is an integer number (22480549).

Almost surely, 2^217313825 is an apocalyptic number.

217313825 is a gapful number since it is divisible by the number (25) formed by its first and last digit.

It is an amenable number.

217313825 is a deficient number, since it is larger than the sum of its proper divisors (52452763).

217313825 is a wasteful number, since it uses less digits than its factorization.

217313825 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9604 (or 9599 counting only the distinct ones).

The product of its digits is 10080, while the sum is 32.

The square root of 217313825 is about 14741.5679288195. The cubic root of 217313825 is about 601.2140464581.

The spelling of 217313825 in words is "two hundred seventeen million, three hundred thirteen thousand, eight hundred twenty-five".