78473261 has 2 divisors, whose sum is σ = 78473262. Its totient is φ = 78473260.

The previous prime is 78473257. The next prime is 78473273. The reversal of 78473261 is 16237487.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 72148036 + 6325225 = 8494^2 + 2515^2 .

It is a cyclic number.

It is not a de Polignac number, because 78473261 - 2² = 78473257 is a prime.

It is a Sophie Germain prime.

It is a Curzon number.

It is equal to p_4585475 and since 78473261 and 4585475 have the same sum of digits, it is a Honaker prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (78473201) 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 as a sum of consecutive naturals, namely, 39236630 + 39236631.

It is an arithmetic number, because the mean of its divisors is an integer number (39236631).

Almost surely, 2^78473261 is an apocalyptic number.

It is an amenable number.

78473261 is a deficient number, since it is larger than the sum of its proper divisors (1).

78473261 is an equidigital number, since it uses as much as digits as its factorization.

78473261 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 56448, while the sum is 38.

The square root of 78473261 is about 8858.5134757475. The cubic root of 78473261 is about 428.1282642478.

The spelling of 78473261 in words is "seventy-eight million, four hundred seventy-three thousand, two hundred sixty-one".