21100121012 has 12 divisors (see below), whose sum is σ = 37007453700. Its totient is φ = 10526562816.

The previous prime is 21100120973. The next prime is 21100121033. The reversal of 21100121012 is 21012100112.

It can be written as a sum of positive squares in 2 ways, for example, as 13187306896 + 7912814116 = 114836^2 + 88954^2 .

It is a junction number, because it is equal to n+sod(n) for n = 21100120984 and 21100121002.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 5872403 + ... + 5875994.

It is an arithmetic number, because the mean of its divisors is an integer number (3083954475).

Almost surely, 2^21100121012 is an apocalyptic number.

It is an amenable number.

21100121012 is a deficient number, since it is larger than the sum of its proper divisors (15907332688).

21100121012 is a wasteful number, since it uses less digits than its factorization.

21100121012 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 11748850 (or 11748848 counting only the distinct ones).

The product of its (nonzero) digits is 8, while the sum is 11.

Adding to 21100121012 its reverse (21012100112), we get a palindrome (42112221124).

The spelling of 21100121012 in words is "twenty-one billion, one hundred million, one hundred twenty-one thousand, twelve".