20215969809 has 16 divisors (see below), whose sum is σ = 32426618880. Its totient is φ = 10943983440.

The previous prime is 20215969721. The next prime is 20215969843. The reversal of 20215969809 is 90896951202.

It is not a de Polignac number, because 20215969809 - 2⁷ = 20215969681 is a prime.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (20215969859) 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, 25332897 + ... + 25333694.

It is an arithmetic number, because the mean of its divisors is an integer number (2026663680).

Almost surely, 2^20215969809 is an apocalyptic number.

It is an amenable number.

20215969809 is a deficient number, since it is larger than the sum of its proper divisors (12210649071).

20215969809 is a wasteful number, since it uses less digits than its factorization.

20215969809 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 50666620.

The product of its (nonzero) digits is 699840, while the sum is 51.

The spelling of 20215969809 in words is "twenty billion, two hundred fifteen million, nine hundred sixty-nine thousand, eight hundred nine".