20965651211 has 4 divisors (see below), whose sum is σ = 21000536424. Its totient is φ = 20930766000.

The previous prime is 20965651207. The next prime is 20965651277. The reversal of 20965651211 is 11215656902.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 11215656902 = 2 ⋅5607828451.

It is a cyclic number.

It is not a de Polignac number, because 20965651211 - 2² = 20965651207 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (20965651111) 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 3 ways as a sum of consecutive naturals, for example, 17441705 + ... + 17442906.

It is an arithmetic number, because the mean of its divisors is an integer number (5250134106).

Almost surely, 2^20965651211 is an apocalyptic number.

20965651211 is a deficient number, since it is larger than the sum of its proper divisors (34885213).

20965651211 is an equidigital number, since it uses as much as digits as its factorization.

20965651211 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 34885212.

The product of its (nonzero) digits is 32400, while the sum is 38.

The spelling of 20965651211 in words is "twenty billion, nine hundred sixty-five million, six hundred fifty-one thousand, two hundred eleven".