231391145 has 8 divisors (see below), whose sum is σ = 287244360. Its totient is φ = 178729600.

The previous prime is 231391129. The next prime is 231391151. The reversal of 231391145 is 541193132.

It can be written as a sum of positive squares in 4 ways, for example, as 28955161 + 202435984 = 5381^2 + 14228^2 .

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

It is not a de Polignac number, because 231391145 - 2⁴ = 231391129 is a prime.

It is a super-2 number, since 2×231391145² = 107083723968822050, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (29).

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, 797756 + ... + 798045.

It is an arithmetic number, because the mean of its divisors is an integer number (35905545).

Almost surely, 2^231391145 is an apocalyptic number.

It is an amenable number.

231391145 is a deficient number, since it is larger than the sum of its proper divisors (55853215).

231391145 is a wasteful number, since it uses less digits than its factorization.

231391145 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1595835.

The product of its digits is 3240, while the sum is 29.

The square root of 231391145 is about 15211.5464368354. The cubic root of 231391145 is about 613.9253667946.

The spelling of 231391145 in words is "two hundred thirty-one million, three hundred ninety-one thousand, one hundred forty-five".