231138513 has 24 divisors (see below), whose sum is σ = 341009760. Its totient is φ = 150828480.

The previous prime is 231138503. The next prime is 231138541. The reversal of 231138513 is 315831132.

It is not a de Polignac number, because 231138513 - 2¹³ = 231130321 is a prime.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (231138503) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 90058 + ... + 92588.

It is an arithmetic number, because the mean of its divisors is an integer number (14208740).

Almost surely, 2^231138513 is an apocalyptic number.

It is an amenable number.

231138513 is a deficient number, since it is larger than the sum of its proper divisors (109871247).

231138513 is a wasteful number, since it uses less digits than its factorization.

231138513 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2749 (or 2746 counting only the distinct ones).

The product of its digits is 2160, while the sum is 27.

The square root of 231138513 is about 15203.2402138492. The cubic root of 231138513 is about 613.7018582814.

Adding to 231138513 its reverse (315831132), we get a palindrome (546969645).

It can be divided in two parts, 23113 and 8513, that added together give a triangular number (31626 = T₂₅₁).

The spelling of 231138513 in words is "two hundred thirty-one million, one hundred thirty-eight thousand, five hundred thirteen".