21161072106 has 36 divisors (see below), whose sum is σ = 46298864898. Its totient is φ = 6985145232.

The previous prime is 21161072071. The next prime is 21161072117. The reversal of 21161072106 is 60127016112.

It is a happy number.

21161072106 is a `hidden beast` number, since 21 + 1 + 610 + 7 + 21 + 0 + 6 = 666.

It can be written as a sum of positive squares in only one way, i.e., 19420930881 + 1740141225 = 139359^2 + 41715^2 .

It is a self number, because there is not a number n which added to its sum of digits gives 21161072106.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 17 ways as a sum of consecutive naturals, for example, 135556 + ... + 246368.

Almost surely, 2^21161072106 is an apocalyptic number.

21161072106 is an abundant number, since it is smaller than the sum of its proper divisors (25137792792).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

21161072106 is a wasteful number, since it uses less digits than its factorization.

21161072106 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 111027 (or 110921 counting only the distinct ones).

The product of its (nonzero) digits is 1008, while the sum is 27.

Adding to 21161072106 its reverse (60127016112), we get a palindrome (81288088218).

The spelling of 21161072106 in words is "twenty-one billion, one hundred sixty-one million, seventy-two thousand, one hundred six".