781656489 has 6 divisors (see below), whose sum is σ = 1129059386. Its totient is φ = 521104320.

The previous prime is 781656461. The next prime is 781656497. The reversal of 781656489 is 984656187.

781656489 is a `hidden beast` number, since 78 + 1 + 6 + 564 + 8 + 9 = 666.

781656489 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It can be written as a sum of positive squares in only one way, i.e., 485541225 + 296115264 = 22035^2 + 17208^2 .

It is not a de Polignac number, because 781656489 - 2⁵ = 781656457 is a prime.

It is a super-2 number, since 2×781656489² = 1221973733591614242, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (781656439) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 43425352 + ... + 43425369.

Almost surely, 2^781656489 is an apocalyptic number.

It is an amenable number.

781656489 is a deficient number, since it is larger than the sum of its proper divisors (347402897).

781656489 is a wasteful number, since it uses less digits than its factorization.

781656489 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 86850727 (or 86850724 counting only the distinct ones).

The product of its digits is 2903040, while the sum is 54.

The square root of 781656489 is about 27958.1202694316. The cubic root of 781656489 is about 921.1675822475.

The spelling of 781656489 in words is "seven hundred eighty-one million, six hundred fifty-six thousand, four hundred eighty-nine".