21779848 has 16 divisors (see below), whose sum is σ = 40888080. Its totient is φ = 10876368.

The previous prime is 21779837. The next prime is 21779851. The reversal of 21779848 is 84897712.

It is a junction number, because it is equal to n+sod(n) for n = 21779798 and 21779807.

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, 9415 + ... + 11497.

It is an arithmetic number, because the mean of its divisors is an integer number (2555505).

Almost surely, 2^21779848 is an apocalyptic number.

It is an amenable number.

21779848 is a deficient number, since it is larger than the sum of its proper divisors (19108232).

21779848 is a wasteful number, since it uses less digits than its factorization.

21779848 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3396 (or 3392 counting only the distinct ones).

The product of its digits is 225792, while the sum is 46.

The square root of 21779848 is about 4666.8884709194. Note that the first 3 decimals coincide. The cubic root of 21779848 is about 279.2661395076.

The spelling of 21779848 in words is "twenty-one million, seven hundred seventy-nine thousand, eight hundred forty-eight".