231556013 has 4 divisors (see below), whose sum is σ = 249368028. Its totient is φ = 213744000.

The previous prime is 231556009. The next prime is 231556033. The reversal of 231556013 is 310655132.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 106048804 + 125507209 = 10298^2 + 11203^2 .

It is a cyclic number.

It is not a de Polignac number, because 231556013 - 2² = 231556009 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (231556033) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 8905988 + ... + 8906013.

It is an arithmetic number, because the mean of its divisors is an integer number (62342007).

Almost surely, 2^231556013 is an apocalyptic number.

It is an amenable number.

231556013 is a deficient number, since it is larger than the sum of its proper divisors (17812015).

231556013 is a wasteful number, since it uses less digits than its factorization.

231556013 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 17812014.

The product of its (nonzero) digits is 2700, while the sum is 26.

The square root of 231556013 is about 15216.9646447641. The cubic root of 231556013 is about 614.0711410529.

The spelling of 231556013 in words is "two hundred thirty-one million, five hundred fifty-six thousand, thirteen".