20506654505 has 16 divisors (see below), whose sum is σ = 25439475600. Its totient is φ = 15858339840.

The previous prime is 20506654501. The next prime is 20506654517. The reversal of 20506654505 is 50545660502.

It is a happy number.

It can be written as a sum of positive squares in 8 ways, for example, as 3744950416 + 16761704089 = 61196^2 + 129467^2 .

It is not a de Polignac number, because 20506654505 - 2² = 20506654501 is a prime.

It is not an unprimeable number, because it can be changed into a prime (20506654501) 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 15 ways as a sum of consecutive naturals, for example, 436520 + ... + 481209.

It is an arithmetic number, because the mean of its divisors is an integer number (1589967225).

Almost surely, 2^20506654505 is an apocalyptic number.

It is an amenable number.

20506654505 is a deficient number, since it is larger than the sum of its proper divisors (4932821095).

20506654505 is a wasteful number, since it uses less digits than its factorization.

20506654505 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 917884.

The product of its (nonzero) digits is 180000, while the sum is 38.

The spelling of 20506654505 in words is "twenty billion, five hundred six million, six hundred fifty-four thousand, five hundred five".