781955390087 has 2 divisors, whose sum is σ = 781955390088. Its totient is φ = 781955390086.

The previous prime is 781955390077. The next prime is 781955390119. The reversal of 781955390087 is 780093559187.

It is a weak prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-781955390087 is a prime.

It is a super-2 number, since 2×781955390087² (a number of 25 digits) contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (781955390077) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 390977695043 + 390977695044.

It is an arithmetic number, because the mean of its divisors is an integer number (390977695044).

Almost surely, 2^781955390087 is an apocalyptic number.

781955390087 is a deficient number, since it is larger than the sum of its proper divisors (1).

781955390087 is an equidigital number, since it uses as much as digits as its factorization.

781955390087 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 19051200, while the sum is 62.

The spelling of 781955390087 in words is "seven hundred eighty-one billion, nine hundred fifty-five million, three hundred ninety thousand, eighty-seven".