78391336 has 8 divisors (see below), whose sum is σ = 146983770. Its totient is φ = 39195664.

The previous prime is 78391309. The next prime is 78391349. The reversal of 78391336 is 63319387.

It can be written as a sum of positive squares in only one way, i.e., 45832900 + 32558436 = 6770^2 + 5706^2 .

It is a tau number, because it is divible by the number of its divisors (8).

It is a super-2 number, since 2×78391336² = 12290403119729792, which contains 22 as substring.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 4899451 + ... + 4899466.

Almost surely, 2^78391336 is an apocalyptic number.

It is an amenable number.

78391336 is a deficient number, since it is larger than the sum of its proper divisors (68592434).

78391336 is a wasteful number, since it uses less digits than its factorization.

78391336 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9798923 (or 9798919 counting only the distinct ones).

The product of its digits is 81648, while the sum is 40.

The square root of 78391336 is about 8853.8881854245. Note that the first 3 decimals coincide. The cubic root of 78391336 is about 427.9792257073.

The spelling of 78391336 in words is "seventy-eight million, three hundred ninety-one thousand, three hundred thirty-six".