21200120170 has 16 divisors (see below), whose sum is σ = 38269564200. Its totient is φ = 8455748544.

The previous prime is 21200120167. The next prime is 21200120171. The reversal of 21200120170 is 7102100212.

It can be written as a sum of positive squares in 4 ways, for example, as 13297087969 + 7903032201 = 115313^2 + 88899^2 .

It is not an unprimeable number, because it can be changed into a prime (21200120171) 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 7 ways as a sum of consecutive naturals, for example, 3033777 + ... + 3040756.

Almost surely, 2^21200120170 is an apocalyptic number.

21200120170 is a deficient number, since it is larger than the sum of its proper divisors (17069444030).

21200120170 is a wasteful number, since it uses less digits than its factorization.

21200120170 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6074889.

The product of its (nonzero) digits is 56, while the sum is 16.

Adding to 21200120170 its reverse (7102100212), we get a palindrome (28302220382).

The spelling of 21200120170 in words is "twenty-one billion, two hundred million, one hundred twenty thousand, one hundred seventy".