21853525686887 has 4 divisors (see below), whose sum is σ = 21853567289400. Its totient is φ = 21853484084376.

The previous prime is 21853525686869. The next prime is 21853525686947. The reversal of 21853525686887 is 78868652535812.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 21853525686887 - 2¹⁰ = 21853525685863 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21853525686857) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 20003108 + ... + 21067305.

It is an arithmetic number, because the mean of its divisors is an integer number (5463391822350).

Almost surely, 2^{21853525686887} is an apocalyptic number.

21853525686887 is a deficient number, since it is larger than the sum of its proper divisors (41602513).

21853525686887 is an equidigital number, since it uses as much as digits as its factorization.

21853525686887 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 41602512.

The product of its digits is 1548288000, while the sum is 74.

The spelling of 21853525686887 in words is "twenty-one trillion, eight hundred fifty-three billion, five hundred twenty-five million, six hundred eighty-six thousand, eight hundred eighty-seven".