1906557777191 has 2 divisors, whose sum is σ = 1906557777192. Its totient is φ = 1906557777190.

The previous prime is 1906557777119. The next prime is 1906557777193. The reversal of 1906557777191 is 1917777556091.

Together with previous prime (1906557777119) it forms an Ormiston pair, because they use the same digits, order apart.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1906557777191 is a prime.

Together with 1906557777193, it forms a pair of twin primes.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1906557777193) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 953278888595 + 953278888596.

It is an arithmetic number, because the mean of its divisors is an integer number (953278888596).

Almost surely, 2^{1906557777191} is an apocalyptic number.

1906557777191 is a deficient number, since it is larger than the sum of its proper divisors (1).

1906557777191 is an equidigital number, since it uses as much as digits as its factorization.

1906557777191 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 29172150, while the sum is 65.

The spelling of 1906557777191 in words is "one trillion, nine hundred six billion, five hundred fifty-seven million, seven hundred seventy-seven thousand, one hundred ninety-one".