78399447 has 16 divisors (see below), whose sum is σ = 121251072. Its totient is φ = 44130240.

The previous prime is 78399437. The next prime is 78399473. The reversal of 78399447 is 74499387.

It is a happy number.

It is not a de Polignac number, because 78399447 - 2¹¹ = 78397399 is a prime.

It is a super-2 number, since 2×78399447² = 12292946579811618, which contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 78399447.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (78399437) 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, 26454 + ... + 29267.

It is an arithmetic number, because the mean of its divisors is an integer number (7578192).

Almost surely, 2^78399447 is an apocalyptic number.

78399447 is a deficient number, since it is larger than the sum of its proper divisors (42851625).

78399447 is a wasteful number, since it uses less digits than its factorization.

78399447 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 55798.

The product of its digits is 1524096, while the sum is 51.

The square root of 78399447 is about 8854.3462209245. The cubic root of 78399447 is about 427.9939859259.

The spelling of 78399447 in words is "seventy-eight million, three hundred ninety-nine thousand, four hundred forty-seven".