242515813 has 4 divisors (see below), whose sum is σ = 246135520. Its totient is φ = 238896108.

The previous prime is 242515799. The next prime is 242515831. The reversal of 242515813 is 318515242.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also an emirpimes, since its reverse is a distinct semiprime: 318515242 = 2 ⋅159257621.

It is a cyclic number.

It is not a de Polignac number, because 242515813 - 2⁵ = 242515781 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 (242515853) 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, 1809753 + ... + 1809886.

It is an arithmetic number, because the mean of its divisors is an integer number (61533880).

Almost surely, 2^242515813 is an apocalyptic number.

It is an amenable number.

242515813 is a deficient number, since it is larger than the sum of its proper divisors (3619707).

242515813 is an equidigital number, since it uses as much as digits as its factorization.

242515813 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3619706.

The product of its digits is 9600, while the sum is 31.

The square root of 242515813 is about 15572.9192189519. The cubic root of 242515813 is about 623.6104064976.

The spelling of 242515813 in words is "two hundred forty-two million, five hundred fifteen thousand, eight hundred thirteen".