21340375165 has 16 divisors (see below), whose sum is σ = 25736973696. Its totient is φ = 16986760000.

The previous prime is 21340375163. The next prime is 21340375171. The reversal of 21340375165 is 56157304312.

It is not a de Polignac number, because 21340375165 - 2¹ = 21340375163 is a prime.

It is a super-2 number, since 2×21340375165² (a number of 21 digits) contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21340375163) 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, 1285659 + ... + 1302151.

It is an arithmetic number, because the mean of its divisors is an integer number (1608560856).

Almost surely, 2^21340375165 is an apocalyptic number.

It is an amenable number.

21340375165 is a deficient number, since it is larger than the sum of its proper divisors (4396598531).

21340375165 is a wasteful number, since it uses less digits than its factorization.

21340375165 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 17780.

The product of its (nonzero) digits is 75600, while the sum is 37.

Adding to 21340375165 its reverse (56157304312), we get a palindrome (77497679477).

The spelling of 21340375165 in words is "twenty-one billion, three hundred forty million, three hundred seventy-five thousand, one hundred sixty-five".