2165318421 has 16 divisors (see below), whose sum is σ = 3300739200. Its totient is φ = 1236872448.

The previous prime is 2165318399. The next prime is 2165318423. The reversal of 2165318421 is 1248135612.

It is not a de Polignac number, because 2165318421 - 2⁶ = 2165318357 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2165318423) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 44985 + ... + 79713.

It is an arithmetic number, because the mean of its divisors is an integer number (206296200).

Almost surely, 2^2165318421 is an apocalyptic number.

2165318421 is a gapful number since it is divisible by the number (21) formed by its first and last digit.

It is an amenable number.

2165318421 is a deficient number, since it is larger than the sum of its proper divisors (1135420779).

2165318421 is a wasteful number, since it uses less digits than its factorization.

2165318421 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 37708.

The product of its digits is 11520, while the sum is 33.

The square root of 2165318421 is about 46532.9820772321. The cubic root of 2165318421 is about 1293.7208880284.

The spelling of 2165318421 in words is "two billion, one hundred sixty-five million, three hundred eighteen thousand, four hundred twenty-one".