21971848 has 8 divisors (see below), whose sum is σ = 41197230. Its totient is φ = 10985920.

The previous prime is 21971827. The next prime is 21971849. The reversal of 21971848 is 84817912.

It is a happy number.

It can be written as a sum of positive squares in only one way, i.e., 17123044 + 4848804 = 4138^2 + 2202^2 .

It is a tau number, because it is divible by the number of its divisors (8).

It is a self number, because there is not a number n which added to its sum of digits gives 21971848.

It is not an unprimeable number, because it can be changed into a prime (21971849) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1373233 + ... + 1373248.

Almost surely, 2^21971848 is an apocalyptic number.

It is an amenable number.

21971848 is a deficient number, since it is larger than the sum of its proper divisors (19225382).

21971848 is a wasteful number, since it uses less digits than its factorization.

21971848 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2746487 (or 2746483 counting only the distinct ones).

The product of its digits is 32256, while the sum is 40.

The square root of 21971848 is about 4687.4137858738. The cubic root of 21971848 is about 280.0843623347.

The spelling of 21971848 in words is "twenty-one million, nine hundred seventy-one thousand, eight hundred forty-eight".