1906125691 has 2 divisors, whose sum is σ = 1906125692. Its totient is φ = 1906125690.

The previous prime is 1906125677. The next prime is 1906125709. The reversal of 1906125691 is 1965216091.

It is a weak prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1906125691 is a prime.

It is not a weakly prime, because it can be changed into another prime (1906125671) 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 as a sum of consecutive naturals, namely, 953062845 + 953062846.

It is an arithmetic number, because the mean of its divisors is an integer number (953062846).

Almost surely, 2^1906125691 is an apocalyptic number.

1906125691 is a deficient number, since it is larger than the sum of its proper divisors (1).

1906125691 is an equidigital number, since it uses as much as digits as its factorization.

1906125691 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 29160, while the sum is 40.

The square root of 1906125691 is about 43659.1993856965. The cubic root of 1906125691 is about 1239.8919631420.

The spelling of 1906125691 in words is "one billion, nine hundred six million, one hundred twenty-five thousand, six hundred ninety-one".