243997623 has 16 divisors (see below), whose sum is σ = 364681440. Its totient is φ = 161223552.

The previous prime is 243997613. The next prime is 243997631. The reversal of 243997623 is 326799342.

It is not a de Polignac number, because 243997623 - 2⁵ = 243997591 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (243997603) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 36936 + ... + 43037.

It is an arithmetic number, because the mean of its divisors is an integer number (22792590).

Almost surely, 2^243997623 is an apocalyptic number.

243997623 is a deficient number, since it is larger than the sum of its proper divisors (120683817).

243997623 is a wasteful number, since it uses less digits than its factorization.

243997623 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 80095 (or 80089 counting only the distinct ones).

The product of its digits is 489888, while the sum is 45.

The square root of 243997623 is about 15620.4232657121. The cubic root of 243997623 is about 624.8779477934.

The spelling of 243997623 in words is "two hundred forty-three million, nine hundred ninety-seven thousand, six hundred twenty-three".