21849967856 has 20 divisors (see below), whose sum is σ = 42336604272. Its totient is φ = 10924392576.

The previous prime is 21849967837. The next prime is 21849967879. The reversal of 21849967856 is 65876994812.

It is a junction number, because it is equal to n+sod(n) for n = 21849967792 and 21849967801.

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, 562205 + ... + 599811.

Almost surely, 2^21849967856 is an apocalyptic number.

It is an amenable number.

21849967856 is a deficient number, since it is larger than the sum of its proper divisors (20486636416).

21849967856 is a wasteful number, since it uses less digits than its factorization.

21849967856 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 73928 (or 73922 counting only the distinct ones).

The product of its digits is 52254720, while the sum is 65.

The spelling of 21849967856 in words is "twenty-one billion, eight hundred forty-nine million, nine hundred sixty-seven thousand, eight hundred fifty-six".