2165703357421 has 8 divisors (see below), whose sum is σ = 2197943399160. Its totient is φ = 2133639011328.

The previous prime is 2165703357403. The next prime is 2165703357449. The reversal of 2165703357421 is 1247533075612.

It can be written as a sum of positive squares in 4 ways, for example, as 246686055625 + 1919017301796 = 496675^2 + 1385286^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 2165703357421 - 2⁹ = 2165703356909 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 (2165703357481) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 43899076 + ... + 43948381.

It is an arithmetic number, because the mean of its divisors is an integer number (274742924895).

Almost surely, 2^{2165703357421} is an apocalyptic number.

It is an amenable number.

2165703357421 is a deficient number, since it is larger than the sum of its proper divisors (32240041739).

2165703357421 is an equidigital number, since it uses as much as digits as its factorization.

2165703357421 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 87847823.

The product of its (nonzero) digits is 1058400, while the sum is 46.

The spelling of 2165703357421 in words is "two trillion, one hundred sixty-five billion, seven hundred three million, three hundred fifty-seven thousand, four hundred twenty-one".