21855476 has 6 divisors (see below), whose sum is σ = 38247090. Its totient is φ = 10927736.

The previous prime is 21855439. The next prime is 21855487. The reversal of 21855476 is 67455812.

It can be written as a sum of positive squares in only one way, i.e., 21715600 + 139876 = 4660^2 + 374^2 .

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 2731931 + ... + 2731938.

It is an arithmetic number, because the mean of its divisors is an integer number (6374515).

Almost surely, 2^21855476 is an apocalyptic number.

It is an amenable number.

21855476 is a deficient number, since it is larger than the sum of its proper divisors (16391614).

21855476 is a wasteful number, since it uses less digits than its factorization.

21855476 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5463873 (or 5463871 counting only the distinct ones).

The product of its digits is 67200, while the sum is 38.

The square root of 21855476 is about 4674.9840641440. The cubic root of 21855476 is about 279.5890058666.

The spelling of 21855476 in words is "twenty-one million, eight hundred fifty-five thousand, four hundred seventy-six".