217323431 has 8 divisors (see below), whose sum is σ = 234249120. Its totient is φ = 200427552.

The previous prime is 217323413. The next prime is 217323439. The reversal of 217323431 is 134323712.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a de Polignac number, because none of the positive numbers 2^k-217323431 is a prime.

It is a super-2 number, since 2×217323431² = 94458947323223522, which contains 22 as substring.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 217323431.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (217323439) 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, 9065 + ... + 22733.

It is an arithmetic number, because the mean of its divisors is an integer number (29281140).

Almost surely, 2^217323431 is an apocalyptic number.

217323431 is a deficient number, since it is larger than the sum of its proper divisors (16925689).

217323431 is a wasteful number, since it uses less digits than its factorization.

217323431 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 14905.

The product of its digits is 3024, while the sum is 26.

The square root of 217323431 is about 14741.8937385941. The cubic root of 217323431 is about 601.2229048868. Note that the first 3 decimals are identical.

The spelling of 217323431 in words is "two hundred seventeen million, three hundred twenty-three thousand, four hundred thirty-one".