20711021505 has 16 divisors (see below), whose sum is σ = 33260829120. Its totient is φ = 11004813248.

The previous prime is 20711021503. The next prime is 20711021521. The reversal of 20711021505 is 50512011702.

It is a cyclic number.

It is not a de Polignac number, because 20711021505 - 2¹ = 20711021503 is a prime.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (20711021503) 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, 2562387 + ... + 2570456.

It is an arithmetic number, because the mean of its divisors is an integer number (2078801820).

Almost surely, 2^20711021505 is an apocalyptic number.

It is an amenable number.

20711021505 is a deficient number, since it is larger than the sum of its proper divisors (12549807615).

20711021505 is a wasteful number, since it uses less digits than its factorization.

20711021505 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5133120.

The product of its (nonzero) digits is 700, while the sum is 24.

The spelling of 20711021505 in words is "twenty billion, seven hundred eleven million, twenty-one thousand, five hundred five".