2421165865 has 4 divisors (see below), whose sum is σ = 2905399044. Its totient is φ = 1936932688.

The previous prime is 2421165847. The next prime is 2421165871. The reversal of 2421165865 is 5685611242.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 1429671721 + 991494144 = 37811^2 + 31488^2 .

It is a cyclic number.

It is not a de Polignac number, because 2421165865 - 2⁷ = 2421165737 is a prime.

It is a Smith number, since the sum of its digits (40) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a Duffinian number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 242116582 + ... + 242116591.

It is an arithmetic number, because the mean of its divisors is an integer number (726349761).

Almost surely, 2^2421165865 is an apocalyptic number.

It is an amenable number.

2421165865 is a deficient number, since it is larger than the sum of its proper divisors (484233179).

2421165865 is an equidigital number, since it uses as much as digits as its factorization.

2421165865 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 484233178.

The product of its digits is 115200, while the sum is 40.

The square root of 2421165865 is about 49205.3438662916. The cubic root of 2421165865 is about 1342.7902549704.

The spelling of 2421165865 in words is "two billion, four hundred twenty-one million, one hundred sixty-five thousand, eight hundred sixty-five".