20573281 has 4 divisors (see below), whose sum is σ = 21783492. Its totient is φ = 19363072.

The previous prime is 20573269. The next prime is 20573291. The reversal of 20573281 is 18237502.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 18237502 = 2 ⋅9118751.

It can be written as a sum of positive squares in 2 ways, for example, as 16329681 + 4243600 = 4041^2 + 2060^2 .

It is a cyclic number.

It is not a de Polignac number, because 20573281 - 2⁵ = 20573249 is a prime.

It is a super-2 number, since 2×20573281² = 846519782209922, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (20573291) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 605080 + ... + 605113.

It is an arithmetic number, because the mean of its divisors is an integer number (5445873).

Almost surely, 2^20573281 is an apocalyptic number.

It is an amenable number.

20573281 is a deficient number, since it is larger than the sum of its proper divisors (1210211).

20573281 is a wasteful number, since it uses less digits than its factorization.

20573281 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1210210.

The product of its (nonzero) digits is 3360, while the sum is 28.

The square root of 20573281 is about 4535.7778825688. Note that the first 3 decimals coincide. The cubic root of 20573281 is about 274.0109085113.

The spelling of 20573281 in words is "twenty million, five hundred seventy-three thousand, two hundred eighty-one".