78022391 has 2 divisors, whose sum is σ = 78022392. Its totient is φ = 78022390.

The previous prime is 78022363. The next prime is 78022453. The reversal of 78022391 is 19322087.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 78022391 - 2¹⁸ = 77760247 is a prime.

It is a Sophie Germain prime.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (78022291) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 39011195 + 39011196.

It is an arithmetic number, because the mean of its divisors is an integer number (39011196).

Almost surely, 2^78022391 is an apocalyptic number.

78022391 is a deficient number, since it is larger than the sum of its proper divisors (1).

78022391 is an equidigital number, since it uses as much as digits as its factorization.

78022391 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 6048, while the sum is 32.

The square root of 78022391 is about 8833.0284161209. The cubic root of 78022391 is about 427.3067484893.

The spelling of 78022391 in words is "seventy-eight million, twenty-two thousand, three hundred ninety-one".