2091691387 has 2 divisors, whose sum is σ = 2091691388. Its totient is φ = 2091691386.

The previous prime is 2091691379. The next prime is 2091691409. The reversal of 2091691387 is 7831961902.

It is a happy number.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 2091691387 - 2³ = 2091691379 is a prime.

It is not a weakly prime, because it can be changed into another prime (2091691487) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1045845693 + 1045845694.

It is an arithmetic number, because the mean of its divisors is an integer number (1045845694).

Almost surely, 2^2091691387 is an apocalyptic number.

2091691387 is a deficient number, since it is larger than the sum of its proper divisors (1).

2091691387 is an equidigital number, since it uses as much as digits as its factorization.

2091691387 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 163296, while the sum is 46.

The square root of 2091691387 is about 45735.0127036169. The cubic root of 2091691387 is about 1278.8880697920. Note that the first 3 decimals are identical.

The spelling of 2091691387 in words is "two billion, ninety-one million, six hundred ninety-one thousand, three hundred eighty-seven".