21361537228 has 24 divisors (see below), whose sum is σ = 39716938800. Its totient is φ = 10033748928.

The previous prime is 21361537193. The next prime is 21361537231. The reversal of 21361537228 is 82273516312.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 2484238 + ... + 2492821.

It is an arithmetic number, because the mean of its divisors is an integer number (1654872450).

Almost surely, 2^21361537228 is an apocalyptic number.

It is an amenable number.

21361537228 is a deficient number, since it is larger than the sum of its proper divisors (18355401572).

21361537228 is a wasteful number, since it uses less digits than its factorization.

21361537228 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4977129 (or 4977127 counting only the distinct ones).

The product of its digits is 120960, while the sum is 40.

The spelling of 21361537228 in words is "twenty-one billion, three hundred sixty-one million, five hundred thirty-seven thousand, two hundred twenty-eight".