78019409 has 16 divisors (see below), whose sum is σ = 89268480. Its totient is φ = 67549440.

The previous prime is 78019387. The next prime is 78019439. The reversal of 78019409 is 90491087.

It is a cyclic number.

It is not a de Polignac number, because 78019409 - 2⁸ = 78019153 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (78019439) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 108152 + ... + 108870.

It is an arithmetic number, because the mean of its divisors is an integer number (5579280).

Almost surely, 2^78019409 is an apocalyptic number.

It is an amenable number.

78019409 is a deficient number, since it is larger than the sum of its proper divisors (11249071).

78019409 is a wasteful number, since it uses less digits than its factorization.

78019409 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1240.

The product of its (nonzero) digits is 18144, while the sum is 38.

The square root of 78019409 is about 8832.8596162285. The cubic root of 78019409 is about 427.3013045608.

The spelling of 78019409 in words is "seventy-eight million, nineteen thousand, four hundred nine".