243997415 has 4 divisors (see below), whose sum is σ = 292796904. Its totient is φ = 195197928.

The previous prime is 243997399. The next prime is 243997423. The reversal of 243997415 is 514799342.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 514799342 = 2 ⋅257399671.

It is a cyclic number.

It is not a de Polignac number, because 243997415 - 2⁴ = 243997399 is a prime.

It is a Duffinian number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 24399737 + ... + 24399746.

It is an arithmetic number, because the mean of its divisors is an integer number (73199226).

Almost surely, 2^243997415 is an apocalyptic number.

243997415 is a deficient number, since it is larger than the sum of its proper divisors (48799489).

243997415 is an equidigital number, since it uses as much as digits as its factorization.

243997415 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 48799488.

The product of its digits is 272160, while the sum is 44.

The square root of 243997415 is about 15620.4166077605. The cubic root of 243997415 is about 624.8777702307.

The spelling of 243997415 in words is "two hundred forty-three million, nine hundred ninety-seven thousand, four hundred fifteen".