79278409 has 4 divisors (see below), whose sum is σ = 90603904. Its totient is φ = 67952916.

The previous prime is 79278371. The next prime is 79278413. The reversal of 79278409 is 90487297.

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: 90487297 = 59 ⋅1533683.

It is a cyclic number.

It is not a de Polignac number, because 79278409 - 2⁹ = 79277897 is a prime.

It is a super-2 number, since 2×79278409² = 12570132267142562, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (79278509) 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 in 3 ways as a sum of consecutive naturals, for example, 5662737 + ... + 5662750.

It is an arithmetic number, because the mean of its divisors is an integer number (22650976).

Almost surely, 2^79278409 is an apocalyptic number.

It is an amenable number.

79278409 is a deficient number, since it is larger than the sum of its proper divisors (11325495).

79278409 is a wasteful number, since it uses less digits than its factorization.

79278409 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 11325494.

The product of its (nonzero) digits is 254016, while the sum is 46.

The square root of 79278409 is about 8903.8423728186. The cubic root of 79278409 is about 429.5875059942.

The spelling of 79278409 in words is "seventy-nine million, two hundred seventy-eight thousand, four hundred nine".