21278044 has 6 divisors (see below), whose sum is σ = 37236584. Its totient is φ = 10639020.

The previous prime is 21278041. The next prime is 21278063. The reversal of 21278044 is 44087212.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21278041) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 2659752 + ... + 2659759.

Almost surely, 2^21278044 is an apocalyptic number.

It is an amenable number.

21278044 is a deficient number, since it is larger than the sum of its proper divisors (15958540).

21278044 is a wasteful number, since it uses less digits than its factorization.

21278044 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5319515 (or 5319513 counting only the distinct ones).

The product of its (nonzero) digits is 3584, while the sum is 28.

The square root of 21278044 is about 4612.8130246087. The cubic root of 21278044 is about 277.1047056887.

The spelling of 21278044 in words is "twenty-one million, two hundred seventy-eight thousand, forty-four".