243125537 has 4 divisors (see below), whose sum is σ = 243241236. Its totient is φ = 243009840.

The previous prime is 243125471. The next prime is 243125563. The reversal of 243125537 is 735521342.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 735521342 = 2 ⋅367760671.

It can be written as a sum of positive squares in 2 ways, for example, as 143904016 + 99221521 = 11996^2 + 9961^2 .

It is a cyclic number.

It is not a de Polignac number, because 243125537 - 2¹⁶ = 243060001 is a prime.

It is a super-2 number, since 2×243125537² = 118220053483076738, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (243125137) 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, 54638 + ... + 58919.

It is an arithmetic number, because the mean of its divisors is an integer number (60810309).

Almost surely, 2^243125537 is an apocalyptic number.

It is an amenable number.

243125537 is a deficient number, since it is larger than the sum of its proper divisors (115699).

243125537 is a wasteful number, since it uses less digits than its factorization.

243125537 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 115698.

The product of its digits is 25200, while the sum is 32.

The square root of 243125537 is about 15592.4833493578. The cubic root of 243125537 is about 624.1325882853.

Adding to 243125537 its reverse (735521342), we get a palindrome (978646879).

The spelling of 243125537 in words is "two hundred forty-three million, one hundred twenty-five thousand, five hundred thirty-seven".