21581675529617 has 16 divisors (see below), whose sum is σ = 25737310759680. Its totient is φ = 17694184814592.

The previous prime is 21581675529587. The next prime is 21581675529637. The reversal of 21581675529617 is 71692557618512.

It is a cyclic number.

It is not a de Polignac number, because 21581675529617 - 2⁶ = 21581675529553 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21581675529637) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 36058433 + ... + 36652065.

It is an arithmetic number, because the mean of its divisors is an integer number (1608581922480).

Almost surely, 2^{21581675529617} is an apocalyptic number.

It is an amenable number.

21581675529617 is a deficient number, since it is larger than the sum of its proper divisors (4155635230063).

21581675529617 is a wasteful number, since it uses less digits than its factorization.

21581675529617 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 819472.

The product of its digits is 63504000, while the sum is 65.

The spelling of 21581675529617 in words is "twenty-one trillion, five hundred eighty-one billion, six hundred seventy-five million, five hundred twenty-nine thousand, six hundred seventeen".