78711409 has 4 divisors (see below), whose sum is σ = 89955904. Its totient is φ = 67466916.

The previous prime is 78711403. The next prime is 78711419. The reversal of 78711409 is 90411787.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also an emirpimes, since its reverse is a distinct semiprime: 90411787 = 79 ⋅1144453.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-78711409 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (78711403) 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 in 3 ways as a sum of consecutive naturals, for example, 5622237 + ... + 5622250.

It is an arithmetic number, because the mean of its divisors is an integer number (22488976).

Almost surely, 2^78711409 is an apocalyptic number.

It is an amenable number.

78711409 is a deficient number, since it is larger than the sum of its proper divisors (11244495).

78711409 is a wasteful number, since it uses less digits than its factorization.

78711409 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 11244494.

The product of its (nonzero) digits is 14112, while the sum is 37.

The square root of 78711409 is about 8871.9450516784. The cubic root of 78711409 is about 428.5609166046.

The spelling of 78711409 in words is "seventy-eight million, seven hundred eleven thousand, four hundred nine".