21005160622171 has 4 divisors (see below), whose sum is σ = 22914720678744. Its totient is φ = 19095600565600.

The previous prime is 21005160622111. The next prime is 21005160622189. The reversal of 21005160622171 is 17122606150012.

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 21005160622171 - 2¹¹ = 21005160620123 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21005160622111) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 954780028270 + ... + 954780028291.

It is an arithmetic number, because the mean of its divisors is an integer number (5728680169686).

Almost surely, 2^{21005160622171} is an apocalyptic number.

21005160622171 is a deficient number, since it is larger than the sum of its proper divisors (1909560056573).

21005160622171 is a wasteful number, since it uses less digits than its factorization.

21005160622171 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1909560056572.

The product of its (nonzero) digits is 10080, while the sum is 34.

Adding to 21005160622171 its reverse (17122606150012), we get a palindrome (38127766772183).

The spelling of 21005160622171 in words is "twenty-one trillion, five billion, one hundred sixty million, six hundred twenty-two thousand, one hundred seventy-one".