21155164361255 has 16 divisors (see below), whose sum is σ = 26879620141440. Its totient is φ = 15928524897792.

The previous prime is 21155164361173. The next prime is 21155164361311. The reversal of 21155164361255 is 55216346155112.

It is a cyclic number.

It is not a de Polignac number, because 21155164361255 - 2¹⁴ = 21155164344871 is a prime.

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, 27614066 + ... + 28369824.

It is an arithmetic number, because the mean of its divisors is an integer number (1679976258840).

Almost surely, 2^{21155164361255} is an apocalyptic number.

21155164361255 is a deficient number, since it is larger than the sum of its proper divisors (5724455780185).

21155164361255 is a wasteful number, since it uses less digits than its factorization.

21155164361255 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1085098.

The product of its digits is 1080000, while the sum is 47.

The spelling of 21155164361255 in words is "twenty-one trillion, one hundred fifty-five billion, one hundred sixty-four million, three hundred sixty-one thousand, two hundred fifty-five".