21020100212 has 6 divisors (see below), whose sum is σ = 36785175378. Its totient is φ = 10510050104.

The previous prime is 21020100163. The next prime is 21020100239. The reversal of 21020100212 is 21200102012.

It is a happy number.

It can be written as a sum of positive squares in only one way, i.e., 19242128656 + 1777971556 = 138716^2 + 42166^2 .

It is a super-2 number, since 2×21020100212² (a number of 21 digits) contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 21020100193 and 21020100202.

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, 2627512523 + ... + 2627512530.

It is an arithmetic number, because the mean of its divisors is an integer number (6130862563).

Almost surely, 2^21020100212 is an apocalyptic number.

It is an amenable number.

21020100212 is a deficient number, since it is larger than the sum of its proper divisors (15765075166).

21020100212 is a wasteful number, since it uses less digits than its factorization.

21020100212 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5255025057 (or 5255025055 counting only the distinct ones).

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

Adding to 21020100212 its reverse (21200102012), we get a palindrome (42220202224).

The spelling of 21020100212 in words is "twenty-one billion, twenty million, one hundred thousand, two hundred twelve".