20540039 has 4 divisors (see below), whose sum is σ = 22120056. Its totient is φ = 18960024.

The previous prime is 20540017. The next prime is 20540053. The reversal of 20540039 is 93004502.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 20540039 - 2²⁰ = 19491463 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 20539996 and 20540023.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20540059) 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, 789989 + ... + 790014.

It is an arithmetic number, because the mean of its divisors is an integer number (5530014).

Almost surely, 2^20540039 is an apocalyptic number.

20540039 is a deficient number, since it is larger than the sum of its proper divisors (1580017).

20540039 is a wasteful number, since it uses less digits than its factorization.

20540039 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1580016.

The product of its (nonzero) digits is 1080, while the sum is 23.

The square root of 20540039 is about 4532.1119800817. Note that the first 3 decimals coincide. The cubic root of 20540039 is about 273.8632480431.

The spelling of 20540039 in words is "twenty million, five hundred forty thousand, thirty-nine".