21010012208 has 20 divisors (see below), whose sum is σ = 41126560440. Its totient is φ = 10396706304.

The previous prime is 21010012201. The next prime is 21010012271. The reversal of 21010012208 is 80221001012.

It is a happy number.

It is a super-2 number, since 2×21010012208² (a number of 21 digits) contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (21010012201) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 6767138 + ... + 6770241.

It is an arithmetic number, because the mean of its divisors is an integer number (2056328022).

Almost surely, 2^21010012208 is an apocalyptic number.

It is an amenable number.

21010012208 is a deficient number, since it is larger than the sum of its proper divisors (20116548232).

21010012208 is a wasteful number, since it uses less digits than its factorization.

21010012208 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 13537484 (or 13537478 counting only the distinct ones).

The product of its (nonzero) digits is 64, while the sum is 17.

The spelling of 21010012208 in words is "twenty-one billion, ten million, twelve thousand, two hundred eight".