78938513 has 2 divisors, whose sum is σ = 78938514. Its totient is φ = 78938512.

The previous prime is 78938473. The next prime is 78938527. The reversal of 78938513 is 31583987.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 42601729 + 36336784 = 6527^2 + 6028^2 .

It is a cyclic number.

It is not a de Polignac number, because 78938513 - 2⁶ = 78938449 is a prime.

It is not a weakly prime, because it can be changed into another prime (78938533) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 39469256 + 39469257.

It is an arithmetic number, because the mean of its divisors is an integer number (39469257).

Almost surely, 2^78938513 is an apocalyptic number.

It is an amenable number.

78938513 is a deficient number, since it is larger than the sum of its proper divisors (1).

78938513 is an equidigital number, since it uses as much as digits as its factorization.

78938513 is an evil number, because the sum of its binary digits is even.

The product of its digits is 181440, while the sum is 44.

The square root of 78938513 is about 8884.7348300329. The cubic root of 78938513 is about 428.9726927520.

The spelling of 78938513 in words is "seventy-eight million, nine hundred thirty-eight thousand, five hundred thirteen".