231217628 has 18 divisors (see below), whose sum is σ = 413612976. Its totient is φ = 113047024.

The previous prime is 231217621. The next prime is 231217661. The reversal of 231217628 is 826712132.

231217628 is digitally balanced in base 2 and base 3, because in such bases it contains all the possibile digits an equal number of times.

It is a junction number, because it is equal to n+sod(n) for n = 231217594 and 231217603.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (231217621) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 207938 + ... + 209046.

Almost surely, 2^231217628 is an apocalyptic number.

It is an amenable number.

231217628 is a deficient number, since it is larger than the sum of its proper divisors (182395348).

231217628 is an equidigital number, since it uses as much as digits as its factorization.

231217628 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2269 (or 1158 counting only the distinct ones).

The product of its digits is 8064, while the sum is 32.

The square root of 231217628 is about 15205.8419036895. The cubic root of 231217628 is about 613.7718703898.

The spelling of 231217628 in words is "two hundred thirty-one million, two hundred seventeen thousand, six hundred twenty-eight".