2091689779 has 2 divisors, whose sum is σ = 2091689780. Its totient is φ = 2091689778.

The previous prime is 2091689729. The next prime is 2091689783. The reversal of 2091689779 is 9779861902.

It is a happy number.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 2091689779 - 2¹³ = 2091681587 is a prime.

It is a super-2 number, since 2×2091689779² = 8750332263146137682, which contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (2091689729) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1045844889 + 1045844890.

It is an arithmetic number, because the mean of its divisors is an integer number (1045844890).

Almost surely, 2^2091689779 is an apocalyptic number.

2091689779 is a deficient number, since it is larger than the sum of its proper divisors (1).

2091689779 is an equidigital number, since it uses as much as digits as its factorization.

2091689779 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 3429216, while the sum is 58.

The square root of 2091689779 is about 45734.9951240841. The cubic root of 2091689779 is about 1278.8877420744.

The spelling of 2091689779 in words is "two billion, ninety-one million, six hundred eighty-nine thousand, seven hundred seventy-nine".