20557072 has 20 divisors (see below), whose sum is σ = 40802076. Its totient is φ = 10027520.

The previous prime is 20557067. The next prime is 20557079. The reversal of 20557072 is 27075502.

It can be written as a sum of positive squares in 2 ways, for example, as 10342656 + 10214416 = 3216^2 + 3196^2 .

It is a self number, because there is not a number n which added to its sum of digits gives 20557072.

It is not an unprimeable number, because it can be changed into a prime (20557079) 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 in 3 ways as a sum of consecutive naturals, for example, 15013 + ... + 16324.

Almost surely, 2^20557072 is an apocalyptic number.

It is an amenable number.

20557072 is a deficient number, since it is larger than the sum of its proper divisors (20245004).

20557072 is a wasteful number, since it uses less digits than its factorization.

20557072 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 31386 (or 31380 counting only the distinct ones).

The product of its (nonzero) digits is 4900, while the sum is 28.

The square root of 20557072 is about 4533.9907366469. The cubic root of 20557072 is about 273.9389282610.

The spelling of 20557072 in words is "twenty million, five hundred fifty-seven thousand, seventy-two".