231505216 has 14 divisors (see below), whose sum is σ = 459393290. Its totient is φ = 115752576.

The previous prime is 231505213. The next prime is 231505217. The reversal of 231505216 is 612505132.

231505216 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It can be written as a sum of positive squares in only one way, i.e., 229825600 + 1679616 = 15160^2 + 1296^2 .

It is a super-3 number, since 3×231505216³ (a number of 26 digits) contains 333 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (231505213) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1808571 + ... + 1808698.

Almost surely, 2^231505216 is an apocalyptic number.

It is an amenable number.

231505216 is a deficient number, since it is larger than the sum of its proper divisors (227888074).

231505216 is an equidigital number, since it uses as much as digits as its factorization.

231505216 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3617281 (or 3617271 counting only the distinct ones).

The product of its (nonzero) digits is 1800, while the sum is 25.

The square root of 231505216 is about 15215.2954621328. The cubic root of 231505216 is about 614.0262343475.

The spelling of 231505216 in words is "two hundred thirty-one million, five hundred five thousand, two hundred sixteen".