781863968 has 18 divisors (see below), whose sum is σ = 1539606159. Its totient is φ = 390852896.

The previous prime is 781863967. The next prime is 781864043. The reversal of 781863968 is 869368187.

It is a happy number.

It is a powerful number, because all its prime factors have an exponent greater than 1 and also an Achilles number because it is not a perfect power.

It can be written as a sum of positive squares in only one way, i.e., 390931984 + 390931984 = 19772^2 + 19772^2 .

It is an ABA number since it can be written as A⋅B^A, here for A=2, B=19772.

It is a super-2 number, since 2×781863968² = 1222622528913410048, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (781863961) by changing a digit.

It is a polite number, since it can be written in 2 ways as a sum of consecutive naturals, for example, 155705 + ... + 160647.

Almost surely, 2^781863968 is an apocalyptic number.

It is an amenable number.

781863968 is a deficient number, since it is larger than the sum of its proper divisors (757742191).

781863968 is an frugal number, since it uses more digits than its factorization.

781863968 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9896 (or 4945 counting only the distinct ones).

The product of its digits is 3483648, while the sum is 56.

The square root of 781863968 is about 27961.8305552408. The cubic root of 781863968 is about 921.2490784136.

The spelling of 781863968 in words is "seven hundred eighty-one million, eight hundred sixty-three thousand, nine hundred sixty-eight".