78088421 has 2 divisors, whose sum is σ = 78088422. Its totient is φ = 78088420.

The previous prime is 78088403. The next prime is 78088457. The reversal of 78088421 is 12488087.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 72012196 + 6076225 = 8486^2 + 2465^2 .

It is an emirp because it is prime and its reverse (12488087) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 78088421 - 2¹⁴ = 78072037 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (78088321) 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, 39044210 + 39044211.

It is an arithmetic number, because the mean of its divisors is an integer number (39044211).

Almost surely, 2^78088421 is an apocalyptic number.

It is an amenable number.

78088421 is a deficient number, since it is larger than the sum of its proper divisors (1).

78088421 is an equidigital number, since it uses as much as digits as its factorization.

78088421 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 28672, while the sum is 38.

The square root of 78088421 is about 8836.7653018511. The cubic root of 78088421 is about 427.4272570961.

The spelling of 78088421 in words is "seventy-eight million, eighty-eight thousand, four hundred twenty-one".