78090449 has 2 divisors, whose sum is σ = 78090450. Its totient is φ = 78090448.

The previous prime is 78090433. The next prime is 78090479. The reversal of 78090449 is 94409087.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 72982849 + 5107600 = 8543^2 + 2260^2 .

It is an emirp because it is prime and its reverse (94409087) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 78090449 - 2⁴ = 78090433 is a prime.

It is not a weakly prime, because it can be changed into another prime (78090409) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 39045224 + 39045225.

It is an arithmetic number, because the mean of its divisors is an integer number (39045225).

Almost surely, 2^78090449 is an apocalyptic number.

It is an amenable number.

78090449 is a deficient number, since it is larger than the sum of its proper divisors (1).

78090449 is an equidigital number, since it uses as much as digits as its factorization.

78090449 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 72576, while the sum is 41.

The square root of 78090449 is about 8836.8800489766. The cubic root of 78090449 is about 427.4309572391.

The spelling of 78090449 in words is "seventy-eight million, ninety thousand, four hundred forty-nine".