78516571 has 6 divisors (see below), whose sum is σ = 91335660. Its totient is φ = 67299876.

The previous prime is 78516547. The next prime is 78516631. The reversal of 78516571 is 17561587.

It is not a de Polignac number, because 78516571 - 2²¹ = 76419419 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (78516541) 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 5 ways as a sum of consecutive naturals, for example, 801141 + ... + 801238.

It is an arithmetic number, because the mean of its divisors is an integer number (15222610).

Almost surely, 2^78516571 is an apocalyptic number.

78516571 is a deficient number, since it is larger than the sum of its proper divisors (12819089).

78516571 is a wasteful number, since it uses less digits than its factorization.

78516571 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1602393 (or 1602386 counting only the distinct ones).

The product of its digits is 58800, while the sum is 40.

The square root of 78516571 is about 8860.9576796191. The cubic root of 78516571 is about 428.2070121964.

The spelling of 78516571 in words is "seventy-eight million, five hundred sixteen thousand, five hundred seventy-one".