78491471 has 2 divisors, whose sum is σ = 78491472. Its totient is φ = 78491470.

The previous prime is 78491377. The next prime is 78491573. The reversal of 78491471 is 17419487.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 78491471 - 2¹⁴ = 78475087 is a prime.

It is a super-3 number, since 3×78491471³ (a number of 25 digits) contains 333 as substring. Note that it is a super-d number also for d = 2.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (78491971) 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 as a sum of consecutive naturals, namely, 39245735 + 39245736.

It is an arithmetic number, because the mean of its divisors is an integer number (39245736).

Almost surely, 2^78491471 is an apocalyptic number.

78491471 is a deficient number, since it is larger than the sum of its proper divisors (1).

78491471 is an equidigital number, since it uses as much as digits as its factorization.

78491471 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 56448, while the sum is 41.

The square root of 78491471 is about 8859.5412409447. The cubic root of 78491471 is about 428.1613779166.

The spelling of 78491471 in words is "seventy-eight million, four hundred ninety-one thousand, four hundred seventy-one".