20556543 has 8 divisors (see below), whose sum is σ = 31324288. Its totient is φ = 11746584.

The previous prime is 20556541. The next prime is 20556551. The reversal of 20556543 is 34565502.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 20556543 - 2¹ = 20556541 is a prime.

It is a super-2 number, since 2×20556543² = 845142920221698, which contains 22 as substring.

It is a Duffinian number.

It is a plaindrome in base 16.

It is a self number, because there is not a number n which added to its sum of digits gives 20556543.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20556541) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 489421 + ... + 489462.

It is an arithmetic number, because the mean of its divisors is an integer number (3915536).

Almost surely, 2^20556543 is an apocalyptic number.

20556543 is a deficient number, since it is larger than the sum of its proper divisors (10767745).

20556543 is an equidigital number, since it uses as much as digits as its factorization.

20556543 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 978893.

The product of its (nonzero) digits is 18000, while the sum is 30.

The square root of 20556543 is about 4533.9323991432. The cubic root of 20556543 is about 273.9365784624.

The spelling of 20556543 in words is "twenty million, five hundred fifty-six thousand, five hundred forty-three".