20553839 has 4 divisors (see below), whose sum is σ = 21635640. Its totient is φ = 19472040.

The previous prime is 20553829. The next prime is 20553847. The reversal of 20553839 is 93835502.

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 20553839 - 2⁴ = 20553823 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 20553799 and 20553808.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20553829) 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, 540872 + ... + 540909.

It is an arithmetic number, because the mean of its divisors is an integer number (5408910).

Almost surely, 2^20553839 is an apocalyptic number.

20553839 is a deficient number, since it is larger than the sum of its proper divisors (1081801).

20553839 is a wasteful number, since it uses less digits than its factorization.

20553839 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1081800.

The product of its (nonzero) digits is 32400, while the sum is 35.

The square root of 20553839 is about 4533.6341934479. The cubic root of 20553839 is about 273.9245667639.

The spelling of 20553839 in words is "twenty million, five hundred fifty-three thousand, eight hundred thirty-nine".