20001573 has 14 divisors (see below), whose sum is σ = 29989734. Its totient is φ = 13333896.

The previous prime is 20001557. The next prime is 20001613. The reversal of 20001573 is 37510002.

It can be written as a sum of positive squares in only one way, i.e., 17288964 + 2712609 = 4158^2 + 1647^2 .

It is not a de Polignac number, because 20001573 - 2⁴ = 20001557 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20001073) 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 13 ways as a sum of consecutive naturals, for example, 12990 + ... + 14447.

Almost surely, 2^20001573 is an apocalyptic number.

It is an amenable number.

20001573 is a deficient number, since it is larger than the sum of its proper divisors (9988161).

20001573 is an frugal number, since it uses more digits than its factorization.

20001573 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 27455 (or 27440 counting only the distinct ones).

The product of its (nonzero) digits is 210, while the sum is 18.

The square root of 20001573 is about 4472.3118182882. The cubic root of 20001573 is about 271.4488777711.

Adding to 20001573 its reverse (37510002), we get a palindrome (57511575).

The spelling of 20001573 in words is "twenty million, one thousand, five hundred seventy-three".