21100020212 has 6 divisors (see below), whose sum is σ = 36925035378. Its totient is φ = 10550010104.

The previous prime is 21100020143. The next prime is 21100020241. The reversal of 21100020212 is 21202000112.

It is a happy number.

It can be written as a sum of positive squares in only one way, i.e., 16199180176 + 4900840036 = 127276^2 + 70006^2 .

It is a junction number, because it is equal to n+sod(n) for n = 21100020193 and 21100020202.

It is a congruent number.

It is an unprimeable number.

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 as a sum of consecutive naturals, namely, 2637502523 + ... + 2637502530.

It is an arithmetic number, because the mean of its divisors is an integer number (6154172563).

Almost surely, 2^21100020212 is an apocalyptic number.

It is an amenable number.

21100020212 is a deficient number, since it is larger than the sum of its proper divisors (15825015166).

21100020212 is a wasteful number, since it uses less digits than its factorization.

21100020212 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5275005057 (or 5275005055 counting only the distinct ones).

The product of its (nonzero) digits is 16, while the sum is 11.

Adding to 21100020212 its reverse (21202000112), we get a palindrome (42302020324).

The spelling of 21100020212 in words is "twenty-one billion, one hundred million, twenty thousand, two hundred twelve".