78520947 has 4 divisors (see below), whose sum is σ = 104694600. Its totient is φ = 52347296.

The previous prime is 78520921. The next prime is 78520963. The reversal of 78520947 is 74902587.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 74902587 = 3 ⋅24967529.

It is a cyclic number.

It is not a de Polignac number, because 78520947 - 2²³ = 70132339 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 78520899 and 78520908.

It is not an unprimeable number, because it can be changed into a prime (78520997) 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, 13086822 + ... + 13086827.

It is an arithmetic number, because the mean of its divisors is an integer number (26173650).

Almost surely, 2^78520947 is an apocalyptic number.

78520947 is a deficient number, since it is larger than the sum of its proper divisors (26173653).

78520947 is a wasteful number, since it uses less digits than its factorization.

78520947 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 26173652.

The product of its (nonzero) digits is 141120, while the sum is 42.

The square root of 78520947 is about 8861.2046020843. The cubic root of 78520947 is about 428.2149672011.

The spelling of 78520947 in words is "seventy-eight million, five hundred twenty thousand, nine hundred forty-seven".