231721056 has 72 divisors (see below), whose sum is σ = 753099984. Its totient is φ = 66205440.

The previous prime is 231721043. The next prime is 231721073. The reversal of 231721056 is 650127132.

It is a happy number.

231721056 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a tau number, because it is divible by the number of its divisors (72).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 55455 + ... + 59486.

It is an arithmetic number, because the mean of its divisors is an integer number (10459722).

Almost surely, 2^231721056 is an apocalyptic number.

It is an amenable number.

231721056 is an abundant number, since it is smaller than the sum of its proper divisors (521378928).

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

231721056 is a wasteful number, since it uses less digits than its factorization.

231721056 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 114964 (or 114953 counting only the distinct ones).

The product of its (nonzero) digits is 2520, while the sum is 27.

The square root of 231721056 is about 15222.3866722666. The cubic root of 231721056 is about 614.2170007562.

Adding to 231721056 its reverse (650127132), we get a palindrome (881848188).

The spelling of 231721056 in words is "two hundred thirty-one million, seven hundred twenty-one thousand, fifty-six".