21079144 has 8 divisors (see below), whose sum is σ = 39523410. Its totient is φ = 10539568.

The previous prime is 21079141. The next prime is 21079153. The reversal of 21079144 is 44197012.

It can be written as a sum of positive squares in only one way, i.e., 12888100 + 8191044 = 3590^2 + 2862^2 .

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

It is not an unprimeable number, because it can be changed into a prime (21079141) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1317439 + ... + 1317454.

Almost surely, 2^21079144 is an apocalyptic number.

It is an amenable number.

21079144 is a deficient number, since it is larger than the sum of its proper divisors (18444266).

21079144 is a wasteful number, since it uses less digits than its factorization.

21079144 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2634899 (or 2634895 counting only the distinct ones).

The product of its (nonzero) digits is 2016, while the sum is 28.

The square root of 21079144 is about 4591.2028924891. The cubic root of 21079144 is about 276.2385740857.

The spelling of 21079144 in words is "twenty-one million, seventy-nine thousand, one hundred forty-four".