21040055533165 has 16 divisors (see below), whose sum is σ = 25930617818112. Its totient is φ = 16377016307904.

The previous prime is 21040055533139. The next prime is 21040055533183. The reversal of 21040055533165 is 56133555004012.

It is a happy number.

It is a cyclic number.

It is not a de Polignac number, because 21040055533165 - 2⁹ = 21040055532653 is a prime.

It is a Duffinian number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 38766802 + ... + 39305788.

It is an arithmetic number, because the mean of its divisors is an integer number (1620663613632).

Almost surely, 2^{21040055533165} is an apocalyptic number.

It is an amenable number.

21040055533165 is a deficient number, since it is larger than the sum of its proper divisors (4890562284947).

21040055533165 is a wasteful number, since it uses less digits than its factorization.

21040055533165 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 750036.

The product of its (nonzero) digits is 270000, while the sum is 40.

The spelling of 21040055533165 in words is "twenty-one trillion, forty billion, fifty-five million, five hundred thirty-three thousand, one hundred sixty-five".