78025809 has 4 divisors (see below), whose sum is σ = 104034416. Its totient is φ = 52017204.

The previous prime is 78025807. The next prime is 78025811. The reversal of 78025809 is 90852087.

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: 90852087 = 3 ⋅30284029.

It is an interprime number because it is at equal distance from previous prime (78025807) and next prime (78025811).

It is not a de Polignac number, because 78025809 - 2¹ = 78025807 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (78025807) 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, 13004299 + ... + 13004304.

It is an arithmetic number, because the mean of its divisors is an integer number (26008604).

Almost surely, 2^78025809 is an apocalyptic number.

It is an amenable number.

78025809 is a deficient number, since it is larger than the sum of its proper divisors (26008607).

78025809 is a wasteful number, since it uses less digits than its factorization.

78025809 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 26008606.

The product of its (nonzero) digits is 40320, while the sum is 39.

The square root of 78025809 is about 8833.2218923788. The cubic root of 78025809 is about 427.3129882072.

The spelling of 78025809 in words is "seventy-eight million, twenty-five thousand, eight hundred nine".