21077072 has 10 divisors (see below), whose sum is σ = 40836858. Its totient is φ = 10538528.

The previous prime is 21077057. The next prime is 21077081. The reversal of 21077072 is 27077012.

It can be written as a sum of positive squares in only one way, i.e., 13808656 + 7268416 = 3716^2 + 2696^2 .

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, 658643 + ... + 658674.

Almost surely, 2^21077072 is an apocalyptic number.

It is an amenable number.

21077072 is a deficient number, since it is larger than the sum of its proper divisors (19759786).

21077072 is a wasteful number, since it uses less digits than its factorization.

21077072 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1317325 (or 1317319 counting only the distinct ones).

The product of its (nonzero) digits is 1372, while the sum is 26.

The square root of 21077072 is about 4590.9772380181. The cubic root of 21077072 is about 276.2295227207.

The spelling of 21077072 in words is "twenty-one million, seventy-seven thousand, seventy-two".