78515573 has 2 divisors, whose sum is σ = 78515574. Its totient is φ = 78515572.

The previous prime is 78515539. The next prime is 78515599. The reversal of 78515573 is 37551587.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 73239364 + 5276209 = 8558^2 + 2297^2 .

It is an emirp because it is prime and its reverse (37551587) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 78515573 - 2⁸ = 78515317 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 78515573.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (78515513) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 39257786 + 39257787.

It is an arithmetic number, because the mean of its divisors is an integer number (39257787).

Almost surely, 2^78515573 is an apocalyptic number.

It is an amenable number.

78515573 is a deficient number, since it is larger than the sum of its proper divisors (1).

78515573 is an equidigital number, since it uses as much as digits as its factorization.

78515573 is an evil number, because the sum of its binary digits is even.

The product of its digits is 147000, while the sum is 41.

The square root of 78515573 is about 8860.9013649854. The cubic root of 78515573 is about 428.2051979194.

The spelling of 78515573 in words is "seventy-eight million, five hundred fifteen thousand, five hundred seventy-three".