243691423 has 4 divisors (see below), whose sum is σ = 243725328. Its totient is φ = 243657520.

The previous prime is 243691421. The next prime is 243691429. The reversal of 243691423 is 324196342.

It is a happy number.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length, and also an emirpimes, since its reverse is a distinct semiprime: 324196342 = 2 ⋅162098171.

It is a cyclic number.

It is not a de Polignac number, because 243691423 - 2¹ = 243691421 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (243691421) 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, 1438 + ... + 22123.

It is an arithmetic number, because the mean of its divisors is an integer number (60931332).

Almost surely, 2^243691423 is an apocalyptic number.

243691423 is a deficient number, since it is larger than the sum of its proper divisors (33905).

243691423 is a wasteful number, since it uses less digits than its factorization.

243691423 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 33904.

The product of its digits is 31104, while the sum is 34.

The square root of 243691423 is about 15610.6189179033. The cubic root of 243691423 is about 624.6164456258.

The spelling of 243691423 in words is "two hundred forty-three million, six hundred ninety-one thousand, four hundred twenty-three".