78936835849 has 3 divisors (see below), whose sum is σ = 78937116807. Its totient is φ = 78936554892.

The previous prime is 78936835847. The next prime is 78936835961. The reversal of 78936835849 is 94853863987.

The square root of 78936835849 is 280957.

It is a perfect power (a square), and thus also a powerful number.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length, and also an emirpimes, since its reverse is a distinct semiprime: 94853863987 = 307 ⋅308970241.

It can be written as a sum of positive squares in only one way, i.e., 3823567225 + 75113268624 = 61835^2 + 274068^2 .

It is not a de Polignac number, because 78936835849 - 2¹ = 78936835847 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (78936835847) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 2 ways as a sum of consecutive naturals, for example, 140479 + ... + 421435.

It is an arithmetic number, because the mean of its divisors is an integer number (26312372269).

Almost surely, 2^78936835849 is an apocalyptic number.

78936835849 is the 280957-th square number.

78936835849 is the 140479-th centered octagonal number.

It is an amenable number.

78936835849 is a deficient number, since it is larger than the sum of its proper divisors (280958).

78936835849 is an frugal number, since it uses more digits than its factorization.

78936835849 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 561914 (or 280957 counting only the distinct ones).

The product of its digits is 313528320, while the sum is 70.

The spelling of 78936835849 in words is "seventy-eight billion, nine hundred thirty-six million, eight hundred thirty-five thousand, eight hundred forty-nine".