71478809 has 2 divisors, whose sum is σ = 71478810. Its totient is φ = 71478808.

The previous prime is 71478769. The next prime is 71478851. The reversal of 71478809 is 90887417.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 71453209 + 25600 = 8453^2 + 160^2 .

It is an emirp because it is prime and its reverse (90887417) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 71478809 - 2¹⁶ = 71413273 is a prime.

It is a Chen prime.

It is a self number, because there is not a number n which added to its sum of digits gives 71478809.

It is not a weakly prime, because it can be changed into another prime (71478409) 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 as a sum of consecutive naturals, namely, 35739404 + 35739405.

It is an arithmetic number, because the mean of its divisors is an integer number (35739405).

Almost surely, 2^71478809 is an apocalyptic number.

It is an amenable number.

71478809 is a deficient number, since it is larger than the sum of its proper divisors (1).

71478809 is an equidigital number, since it uses as much as digits as its factorization.

71478809 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 112896, while the sum is 44.

The square root of 71478809 is about 8454.5141196878. The cubic root of 71478809 is about 415.0105169832.

The spelling of 71478809 in words is "seventy-one million, four hundred seventy-eight thousand, eight hundred nine".