78520577 has 4 divisors (see below), whose sum is σ = 78643716. Its totient is φ = 78397440.

The previous prime is 78520571. The next prime is 78520601. The reversal of 78520577 is 77502587.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 54745201 + 23775376 = 7399^2 + 4876^2 .

It is a cyclic number.

It is not a de Polignac number, because 78520577 - 2¹⁴ = 78504193 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (78520571) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 60608 + ... + 61889.

It is an arithmetic number, because the mean of its divisors is an integer number (19660929).

Almost surely, 2^78520577 is an apocalyptic number.

It is an amenable number.

78520577 is a deficient number, since it is larger than the sum of its proper divisors (123139).

78520577 is a wasteful number, since it uses less digits than its factorization.

78520577 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 123138.

The product of its (nonzero) digits is 137200, while the sum is 41.

The square root of 78520577 is about 8861.1837245370. The cubic root of 78520577 is about 428.2142946001.

It can be divided in two parts, 78520 and 577, that added together give a palindrome (79097).

The spelling of 78520577 in words is "seventy-eight million, five hundred twenty thousand, five hundred seventy-seven".