21228573556 has 6 divisors (see below), whose sum is σ = 37150003730. Its totient is φ = 10614286776.

The previous prime is 21228573493. The next prime is 21228573581. The reversal of 21228573556 is 65537582212.

It can be written as a sum of positive squares in only one way, i.e., 13248010000 + 7980563556 = 115100^2 + 89334^2 .

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, 2653571691 + ... + 2653571698.

Almost surely, 2^21228573556 is an apocalyptic number.

It is an amenable number.

21228573556 is a deficient number, since it is larger than the sum of its proper divisors (15921430174).

21228573556 is a wasteful number, since it uses less digits than its factorization.

21228573556 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5307143393 (or 5307143391 counting only the distinct ones).

The product of its digits is 1008000, while the sum is 46.

The spelling of 21228573556 in words is "twenty-one billion, two hundred twenty-eight million, five hundred seventy-three thousand, five hundred fifty-six".