20439873 has 12 divisors (see below), whose sum is σ = 30322708. Its totient is φ = 13258080.

The previous prime is 20439871. The next prime is 20439911. The reversal of 20439873 is 37893402.

It can be written as a sum of positive squares in 2 ways, for example, as 8661249 + 11778624 = 2943^2 + 3432^2 .

It is not a de Polignac number, because 20439873 - 2¹ = 20439871 is a prime.

It is a super-2 number, since 2×20439873² = 835576816512258, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (20439871) 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 11 ways as a sum of consecutive naturals, for example, 30358 + ... + 31023.

Almost surely, 2^20439873 is an apocalyptic number.

It is an amenable number.

20439873 is a deficient number, since it is larger than the sum of its proper divisors (9882835).

20439873 is a wasteful number, since it uses less digits than its factorization.

20439873 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 61424 (or 61421 counting only the distinct ones).

The product of its (nonzero) digits is 36288, while the sum is 36.

The square root of 20439873 is about 4521.0477767880. The cubic root of 20439873 is about 273.4173466050.

It can be divided in two parts, 20439 and 873, that added together give a palindrome (21312).

The spelling of 20439873 in words is "twenty million, four hundred thirty-nine thousand, eight hundred seventy-three".