20909191193 has 24 divisors (see below), whose sum is σ = 24782624160. Its totient is φ = 17568619200.

The previous prime is 20909191181. The next prime is 20909191207. The reversal of 20909191193 is 39119190902.

It is not a de Polignac number, because 20909191193 - 2¹² = 20909187097 is a prime.

It is not an unprimeable number, because it can be changed into a prime (20909191493) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 16655 + ... + 205172.

It is an arithmetic number, because the mean of its divisors is an integer number (1032609340).

Almost surely, 2^20909191193 is an apocalyptic number.

It is an amenable number.

20909191193 is a deficient number, since it is larger than the sum of its proper divisors (3873432967).

20909191193 is a wasteful number, since it uses less digits than its factorization.

20909191193 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 221909 (or 221898 counting only the distinct ones).

The product of its (nonzero) digits is 39366, while the sum is 44.

The spelling of 20909191193 in words is "twenty billion, nine hundred nine million, one hundred ninety-one thousand, one hundred ninety-three".