21474350165 has 8 divisors (see below), whose sum is σ = 25835467320. Its totient is φ = 17135315392.

The previous prime is 21474350119. The next prime is 21474350171. The reversal of 21474350165 is 56105347412.

It can be written as a sum of positive squares in 4 ways, for example, as 490799716 + 20983550449 = 22154^2 + 144857^2 .

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 21474350165 - 2⁸ = 21474349909 is a prime.

It is a super-2 number, since 2×21474350165² (a number of 21 digits) contains 22 as substring.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 5518454 + ... + 5522343.

It is an arithmetic number, because the mean of its divisors is an integer number (3229433415).

Almost surely, 2^21474350165 is an apocalyptic number.

It is an amenable number.

21474350165 is a deficient number, since it is larger than the sum of its proper divisors (4361117155).

21474350165 is a wasteful number, since it uses less digits than its factorization.

21474350165 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 11041191.

The product of its (nonzero) digits is 100800, while the sum is 38.

Adding to 21474350165 its reverse (56105347412), we get a palindrome (77579697577).

The spelling of 21474350165 in words is "twenty-one billion, four hundred seventy-four million, three hundred fifty thousand, one hundred sixty-five".