20645443191 has 8 divisors (see below), whose sum is σ = 27527928064. Its totient is φ = 13763293560.

The previous prime is 20645443171. The next prime is 20645443201. The reversal of 20645443191 is 19134454602.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 20645443191 - 2¹¹ = 20645441143 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20645443141) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 167796 + ... + 263526.

It is an arithmetic number, because the mean of its divisors is an integer number (3440991008).

Almost surely, 2^20645443191 is an apocalyptic number.

20645443191 is a deficient number, since it is larger than the sum of its proper divisors (6882484873).

20645443191 is an equidigital number, since it uses as much as digits as its factorization.

20645443191 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 167621.

The product of its (nonzero) digits is 103680, while the sum is 39.

Adding to 20645443191 its reverse (19134454602), we get a palindrome (39779897793).

The spelling of 20645443191 in words is "twenty billion, six hundred forty-five million, four hundred forty-three thousand, one hundred ninety-one".