78304813 has 2 divisors, whose sum is σ = 78304814. Its totient is φ = 78304812.

The previous prime is 78304799. The next prime is 78304841. The reversal of 78304813 is 31840387.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 76003524 + 2301289 = 8718^2 + 1517^2 .

It is a cyclic number.

It is not a de Polignac number, because 78304813 - 2¹⁷ = 78173741 is a prime.

It is a super-2 number, since 2×78304813² = 12263287477929938, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (78304883) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 39152406 + 39152407.

It is an arithmetic number, because the mean of its divisors is an integer number (39152407).

Almost surely, 2^78304813 is an apocalyptic number.

It is an amenable number.

78304813 is a deficient number, since it is larger than the sum of its proper divisors (1).

78304813 is an equidigital number, since it uses as much as digits as its factorization.

78304813 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 16128, while the sum is 34.

The square root of 78304813 is about 8849.0006780427. Note that the first 3 decimals coincide. The cubic root of 78304813 is about 427.8217096664.

The spelling of 78304813 in words is "seventy-eight million, three hundred four thousand, eight hundred thirteen".