21230533556 has 12 divisors (see below), whose sum is σ = 38434586820. Its totient is φ = 10249223040.

The previous prime is 21230533477. The next prime is 21230533559. The reversal of 21230533556 is 65533503212.

It can be written as a sum of positive squares in 2 ways, for example, as 11610062500 + 9620471056 = 107750^2 + 98084^2 .

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21230533559) 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, 91510805 + ... + 91511036.

It is an arithmetic number, because the mean of its divisors is an integer number (3202882235).

Almost surely, 2^21230533556 is an apocalyptic number.

It is an amenable number.

21230533556 is a deficient number, since it is larger than the sum of its proper divisors (17204053264).

21230533556 is a wasteful number, since it uses less digits than its factorization.

21230533556 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 183021874 (or 183021872 counting only the distinct ones).

The product of its (nonzero) digits is 81000, while the sum is 35.

The spelling of 21230533556 in words is "twenty-one billion, two hundred thirty million, five hundred thirty-three thousand, five hundred fifty-six".