21057610012817 has 16 divisors (see below), whose sum is σ = 24750265962240. Its totient is φ = 17537402570688.

The previous prime is 21057610012799. The next prime is 21057610012921. The reversal of 21057610012817 is 71821001675012.

It is not a de Polignac number, because 21057610012817 - 2¹⁸ = 21057609750673 is a prime.

It is not an unprimeable number, because it can be changed into a prime (21057610042817) 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 15 ways as a sum of consecutive naturals, for example, 55728842 + ... + 56105427.

It is an arithmetic number, because the mean of its divisors is an integer number (1546891622640).

Almost surely, 2^{21057610012817} is an apocalyptic number.

It is an amenable number.

21057610012817 is a deficient number, since it is larger than the sum of its proper divisors (3692655949423).

21057610012817 is a wasteful number, since it uses less digits than its factorization.

21057610012817 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 111835040.

The product of its (nonzero) digits is 47040, while the sum is 41.

Adding to 21057610012817 its reverse (71821001675012), we get a palindrome (92878611687829).

The spelling of 21057610012817 in words is "twenty-one trillion, fifty-seven billion, six hundred ten million, twelve thousand, eight hundred seventeen".