780339981 has 4 divisors (see below), whose sum is σ = 1040453312. Its totient is φ = 520226652.

The previous prime is 780339971. The next prime is 780340061. The reversal of 780339981 is 189933087.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also an emirpimes, since its reverse is a distinct semiprime: 189933087 = 3 ⋅63311029.

It is not a de Polignac number, because 780339981 - 2⁵ = 780339949 is a prime.

It is a super-2 number, since 2×780339981² = 1217860971894160722, which contains 22 as substring.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 780339981.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (780339941) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 130056661 + ... + 130056666.

It is an arithmetic number, because the mean of its divisors is an integer number (260113328).

Almost surely, 2^780339981 is an apocalyptic number.

It is an amenable number.

780339981 is a deficient number, since it is larger than the sum of its proper divisors (260113331).

780339981 is a wasteful number, since it uses less digits than its factorization.

780339981 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 260113330.

The product of its (nonzero) digits is 326592, while the sum is 48.

The square root of 780339981 is about 27934.5660607069. The cubic root of 780339981 is about 920.6501315977.

The spelling of 780339981 in words is "seven hundred eighty million, three hundred thirty-nine thousand, nine hundred eighty-one".