78578247 has 20 divisors (see below), whose sum is σ = 115311800. Its totient is φ = 47596560.

The previous prime is 78578239. The next prime is 78578249. The reversal of 78578247 is 74287587.

It is a happy number.

It is not a de Polignac number, because 78578247 - 2³ = 78578239 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 78578196 and 78578205.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (78578249) by changing a digit.

It is a polite number, since it can be written in 19 ways as a sum of consecutive naturals, for example, 43029 + ... + 44817.

It is an arithmetic number, because the mean of its divisors is an integer number (5765590).

Almost surely, 2^78578247 is an apocalyptic number.

78578247 is a deficient number, since it is larger than the sum of its proper divisors (36733553).

78578247 is an equidigital number, since it uses as much as digits as its factorization.

78578247 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1836 (or 1803 counting only the distinct ones).

The product of its digits is 878080, while the sum is 48.

The square root of 78578247 is about 8864.4372071779. The cubic root of 78578247 is about 428.3191039632.

The spelling of 78578247 in words is "seventy-eight million, five hundred seventy-eight thousand, two hundred forty-seven".