21170171641 has 4 divisors (see below), whose sum is σ = 21375707392. Its totient is φ = 20964635892.

The previous prime is 21170171629. The next prime is 21170171663. The reversal of 21170171641 is 14617107112.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 21170171641 - 2¹⁹ = 21169647353 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21170171611) 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, 102767721 + ... + 102767926.

It is an arithmetic number, because the mean of its divisors is an integer number (5343926848).

Almost surely, 2^21170171641 is an apocalyptic number.

It is an amenable number.

21170171641 is a deficient number, since it is larger than the sum of its proper divisors (205535751).

21170171641 is a wasteful number, since it uses less digits than its factorization.

21170171641 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 205535750.

The product of its (nonzero) digits is 2352, while the sum is 31.

Adding to 21170171641 its reverse (14617107112), we get a palindrome (35787278753).

The spelling of 21170171641 in words is "twenty-one billion, one hundred seventy million, one hundred seventy-one thousand, six hundred forty-one".