78437389 has 2 divisors, whose sum is σ = 78437390. Its totient is φ = 78437388.

The previous prime is 78437341. The next prime is 78437413. The reversal of 78437389 is 98373487.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 66292164 + 12145225 = 8142^2 + 3485^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-78437389 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (78437329) 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 as a sum of consecutive naturals, namely, 39218694 + 39218695.

It is an arithmetic number, because the mean of its divisors is an integer number (39218695).

Almost surely, 2^78437389 is an apocalyptic number.

It is an amenable number.

78437389 is a deficient number, since it is larger than the sum of its proper divisors (1).

78437389 is an equidigital number, since it uses as much as digits as its factorization.

78437389 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 1016064, while the sum is 49.

The square root of 78437389 is about 8856.4885253694. The cubic root of 78437389 is about 428.0630184233.

The spelling of 78437389 in words is "seventy-eight million, four hundred thirty-seven thousand, three hundred eighty-nine".