21115345323165 has 16 divisors (see below), whose sum is σ = 34874376792576. Its totient is φ = 10898242747200.

The previous prime is 21115345323143. The next prime is 21115345323173. The reversal of 21115345323165 is 56132354351112.

It is not a de Polignac number, because 21115345323165 - 2⁵ = 21115345323133 is a prime.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 22704671926 + ... + 22704672855.

It is an arithmetic number, because the mean of its divisors is an integer number (2179648549536).

Almost surely, 2^{21115345323165} is an apocalyptic number.

It is an amenable number.

21115345323165 is a deficient number, since it is larger than the sum of its proper divisors (13759031469411).

21115345323165 is a wasteful number, since it uses less digits than its factorization.

21115345323165 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 45409344820.

The product of its digits is 324000, while the sum is 42.

Adding to 21115345323165 its reverse (56132354351112), we get a palindrome (77247699674277).

The spelling of 21115345323165 in words is "twenty-one trillion, one hundred fifteen billion, three hundred forty-five million, three hundred twenty-three thousand, one hundred sixty-five".