20521161171 has 96 divisors (see below), whose sum is σ = 35522592768. Its totient is φ = 11170042560.

The previous prime is 20521161119. The next prime is 20521161179. The reversal of 20521161171 is 17116112502.

20521161171 is a `hidden beast` number, since 20 + 5 + 21 + 1 + 611 + 7 + 1 = 666.

It is not a de Polignac number, because 20521161171 - 2¹⁰ = 20521160147 is a prime.

It is a super-2 number, since 2×20521161171² (a number of 21 digits) contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (20521161179) by changing a digit.

It is a polite number, since it can be written in 95 ways as a sum of consecutive naturals, for example, 59138620 + ... + 59138966.

It is an arithmetic number, because the mean of its divisors is an integer number (370027008).

Almost surely, 2^20521161171 is an apocalyptic number.

20521161171 is a gapful number since it is divisible by the number (21) formed by its first and last digit.

20521161171 is a deficient number, since it is larger than the sum of its proper divisors (15001431597).

20521161171 is a wasteful number, since it uses less digits than its factorization.

20521161171 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 781 (or 778 counting only the distinct ones).

The product of its (nonzero) digits is 840, while the sum is 27.

Adding to 20521161171 its reverse (17116112502), we get a palindrome (37637273673).

The spelling of 20521161171 in words is "twenty billion, five hundred twenty-one million, one hundred sixty-one thousand, one hundred seventy-one".