243155291 has 4 divisors (see below), whose sum is σ = 243282000. Its totient is φ = 243028584.

The previous prime is 243155279. The next prime is 243155317. The reversal of 243155291 is 192551342.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 192551342 = 2 ⋅96275671.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-243155291 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (243155221) 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, 60431 + ... + 64328.

It is an arithmetic number, because the mean of its divisors is an integer number (60820500).

Almost surely, 2^243155291 is an apocalyptic number.

243155291 is a deficient number, since it is larger than the sum of its proper divisors (126709).

243155291 is a wasteful number, since it uses less digits than its factorization.

243155291 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 126708.

The product of its digits is 10800, while the sum is 32.

The square root of 243155291 is about 15593.4374337412. The cubic root of 243155291 is about 624.1580479494.

The spelling of 243155291 in words is "two hundred forty-three million, one hundred fifty-five thousand, two hundred ninety-one".