20211002191 has 2 divisors, whose sum is σ = 20211002192. Its totient is φ = 20211002190.

The previous prime is 20211002167. The next prime is 20211002243. The reversal of 20211002191 is 19120011202.

It is a happy number.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 20211002191 - 2¹⁷ = 20210871119 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (20211003191) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10105501095 + 10105501096.

It is an arithmetic number, because the mean of its divisors is an integer number (10105501096).

Almost surely, 2^20211002191 is an apocalyptic number.

20211002191 is a deficient number, since it is larger than the sum of its proper divisors (1).

20211002191 is an equidigital number, since it uses as much as digits as its factorization.

20211002191 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 72, while the sum is 19.

Adding to 20211002191 its reverse (19120011202), we get a palindrome (39331013393).

The spelling of 20211002191 in words is "twenty billion, two hundred eleven million, two thousand, one hundred ninety-one".