778981949 has 4 divisors (see below), whose sum is σ = 788842560. Its totient is φ = 769121340.

The previous prime is 778981927. The next prime is 778981991. The reversal of 778981949 is 949189877.

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.

It is a cyclic number.

It is not a de Polignac number, because 778981949 - 2¹² = 778977853 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a junction number, because it is equal to n+sod(n) for n = 778981891 and 778981900.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (778981349) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 4930187 + ... + 4930344.

It is an arithmetic number, because the mean of its divisors is an integer number (197210640).

Almost surely, 2^778981949 is an apocalyptic number.

778981949 is a gapful number since it is divisible by the number (79) formed by its first and last digit.

It is an amenable number.

778981949 is a deficient number, since it is larger than the sum of its proper divisors (9860611).

778981949 is an equidigital number, since it uses as much as digits as its factorization.

778981949 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9860610.

The product of its digits is 9144576, while the sum is 62.

The square root of 778981949 is about 27910.2480999363. The cubic root of 778981949 is about 920.1157498503.

The spelling of 778981949 in words is "seven hundred seventy-eight million, nine hundred eighty-one thousand, nine hundred forty-nine".