781330091 has 2 divisors, whose sum is σ = 781330092. Its totient is φ = 781330090.

The previous prime is 781330061. The next prime is 781330163. The reversal of 781330091 is 190033187.

781330091 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 781330091 - 2¹⁴ = 781313707 is a prime.

It is a super-2 number, since 2×781330091² = 1220953422204136562, which contains 22 as substring.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (781330031) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 390665045 + 390665046.

It is an arithmetic number, because the mean of its divisors is an integer number (390665046).

Almost surely, 2^781330091 is an apocalyptic number.

781330091 is a deficient number, since it is larger than the sum of its proper divisors (1).

781330091 is an equidigital number, since it uses as much as digits as its factorization.

781330091 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 4536, while the sum is 32.

The square root of 781330091 is about 27952.2823933932. The cubic root of 781330091 is about 921.0393464131.

The spelling of 781330091 in words is "seven hundred eighty-one million, three hundred thirty thousand, ninety-one".