21161111110 has 32 divisors (see below), whose sum is σ = 40449598560. Its totient is φ = 7947975168.

The previous prime is 21161111099. The next prime is 21161111119. The reversal of 21161111110 is 1111116112.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21161111119) by changing a digit.

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 15 ways as a sum of consecutive naturals, for example, 471337 + ... + 514276.

It is an arithmetic number, because the mean of its divisors is an integer number (1264049955).

Almost surely, 2^21161111110 is an apocalyptic number.

21161111110 is a deficient number, since it is larger than the sum of its proper divisors (19288487450).

21161111110 is a wasteful number, since it uses less digits than its factorization.

21161111110 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 985752.

The product of its (nonzero) digits is 12, while the sum is 16.

Adding to 21161111110 its reverse (1111116112), we get a palindrome (22272227222).

The spelling of 21161111110 in words is "twenty-one billion, one hundred sixty-one million, one hundred eleven thousand, one hundred ten".