781349089 has 2 divisors, whose sum is σ = 781349090. Its totient is φ = 781349088.

The previous prime is 781349071. The next prime is 781349119. The reversal of 781349089 is 980943187.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 420045025 + 361304064 = 20495^2 + 19008^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-781349089 is a prime.

It is a super-2 number, since 2×781349089² = 1221012797762259842, which contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (781349069) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 390674544 + 390674545.

It is an arithmetic number, because the mean of its divisors is an integer number (390674545).

Almost surely, 2^781349089 is an apocalyptic number.

It is an amenable number.

781349089 is a deficient number, since it is larger than the sum of its proper divisors (1).

781349089 is an equidigital number, since it uses as much as digits as its factorization.

781349089 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 435456, while the sum is 49.

The square root of 781349089 is about 27952.6222204644. The cubic root of 781349089 is about 921.0468113603.

The spelling of 781349089 in words is "seven hundred eighty-one million, three hundred forty-nine thousand, eighty-nine".