1781111913671 has 2 divisors, whose sum is σ = 1781111913672. Its totient is φ = 1781111913670.

The previous prime is 1781111913611. The next prime is 1781111913701. The reversal of 1781111913671 is 1763191111871.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1781111913671 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1781111913611) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 890555956835 + 890555956836.

It is an arithmetic number, because the mean of its divisors is an integer number (890555956836).

Almost surely, 2^{1781111913671} is an apocalyptic number.

1781111913671 is a deficient number, since it is larger than the sum of its proper divisors (1).

1781111913671 is an equidigital number, since it uses as much as digits as its factorization.

1781111913671 is an evil number, because the sum of its binary digits is even.

The product of its digits is 63504, while the sum is 47.

The spelling of 1781111913671 in words is "one trillion, seven hundred eighty-one billion, one hundred eleven million, nine hundred thirteen thousand, six hundred seventy-one".