20556555501 has 8 divisors (see below), whose sum is σ = 27617968224. Its totient is φ = 13599756560.

The previous prime is 20556555433. The next prime is 20556555511. The reversal of 20556555501 is 10555565502.

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

It is a cyclic number.

It is not a de Polignac number, because 20556555501 - 2¹¹ = 20556553453 is a prime.

It is a super-2 number, since 2×20556555501² (a number of 21 digits) contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 20556555501.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20556555511) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 26152986 + ... + 26153771.

It is an arithmetic number, because the mean of its divisors is an integer number (3452246028).

Almost surely, 2^20556555501 is an apocalyptic number.

It is an amenable number.

20556555501 is a deficient number, since it is larger than the sum of its proper divisors (7061412723).

20556555501 is a wasteful number, since it uses less digits than its factorization.

20556555501 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 52306891.

The product of its (nonzero) digits is 187500, while the sum is 39.

It can be divided in two parts, 2055 and 6555501, that added together give a palindrome (6557556).

The spelling of 20556555501 in words is "twenty billion, five hundred fifty-six million, five hundred fifty-five thousand, five hundred one".