20543553 has 6 divisors (see below), whose sum is σ = 29674034. Its totient is φ = 13695696.

The previous prime is 20543539. The next prime is 20543569. The reversal of 20543553 is 35534502.

It can be written as a sum of positive squares in only one way, i.e., 20007729 + 535824 = 4473^2 + 732^2 .

It is not a de Polignac number, because 20543553 - 2¹⁷ = 20412481 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (20543573) 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 5 ways as a sum of consecutive naturals, for example, 1141300 + ... + 1141317.

Almost surely, 2^20543553 is an apocalyptic number.

It is an amenable number.

20543553 is a deficient number, since it is larger than the sum of its proper divisors (9130481).

20543553 is a wasteful number, since it uses less digits than its factorization.

20543553 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2282623 (or 2282620 counting only the distinct ones).

The product of its (nonzero) digits is 9000, while the sum is 27.

The square root of 20543553 is about 4532.4996414782. The cubic root of 20543553 is about 273.8788647058.

The spelling of 20543553 in words is "twenty million, five hundred forty-three thousand, five hundred fifty-three".