21052090228 has 12 divisors (see below), whose sum is σ = 39675093220. Its totient is φ = 9716349312.

The previous prime is 21052090217. The next prime is 21052090273. The reversal of 21052090228 is 82209025012.

It can be written as a sum of positive squares in 2 ways, for example, as 14397120144 + 6654970084 = 119988^2 + 81578^2 .

It is a self number, because there is not a number n which added to its sum of digits gives 21052090228.

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, 202423893 + ... + 202423996.

Almost surely, 2^21052090228 is an apocalyptic number.

It is an amenable number.

21052090228 is a deficient number, since it is larger than the sum of its proper divisors (18623002992).

21052090228 is a wasteful number, since it uses less digits than its factorization.

21052090228 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 404847906 (or 404847904 counting only the distinct ones).

The product of its (nonzero) digits is 5760, while the sum is 31.

The spelling of 21052090228 in words is "twenty-one billion, fifty-two million, ninety thousand, two hundred twenty-eight".