231520145 has 8 divisors (see below), whose sum is σ = 279038760. Its totient is φ = 184406400.

The previous prime is 231520129. The next prime is 231520171. The reversal of 231520145 is 541025132.

It can be written as a sum of positive squares in 4 ways, for example, as 22052416 + 209467729 = 4696^2 + 14473^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 231520145 - 2⁴ = 231520129 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 231520145.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 99956 + ... + 102245.

It is an arithmetic number, because the mean of its divisors is an integer number (34879845).

Almost surely, 2^231520145 is an apocalyptic number.

It is an amenable number.

231520145 is a deficient number, since it is larger than the sum of its proper divisors (47518615).

231520145 is a wasteful number, since it uses less digits than its factorization.

231520145 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 202435.

The product of its (nonzero) digits is 1200, while the sum is 23.

The square root of 231520145 is about 15215.7860460773. The cubic root of 231520145 is about 614.0394328991.

Adding to 231520145 its reverse (541025132), we get a palindrome (772545277).

The spelling of 231520145 in words is "two hundred thirty-one million, five hundred twenty thousand, one hundred forty-five".