2021939191 has 2 divisors, whose sum is σ = 2021939192. Its totient is φ = 2021939190.

The previous prime is 2021939173. The next prime is 2021939197. The reversal of 2021939191 is 1919391202.

It is a happy number.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 2021939191 - 2¹⁵ = 2021906423 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 2021939191.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (2021939197) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1010969595 + 1010969596.

It is an arithmetic number, because the mean of its divisors is an integer number (1010969596).

Almost surely, 2^2021939191 is an apocalyptic number.

2021939191 is a deficient number, since it is larger than the sum of its proper divisors (1).

2021939191 is an equidigital number, since it uses as much as digits as its factorization.

2021939191 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 8748, while the sum is 37.

The square root of 2021939191 is about 44965.9781501526. The cubic root of 2021939191 is about 1264.5112478083.

The spelling of 2021939191 in words is "two billion, twenty-one million, nine hundred thirty-nine thousand, one hundred ninety-one".