78092221 has 2 divisors, whose sum is σ = 78092222. Its totient is φ = 78092220.

The previous prime is 78092191. The next prime is 78092227. The reversal of 78092221 is 12229087.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 58828900 + 19263321 = 7670^2 + 4389^2 .

It is a cyclic number.

It is not a de Polignac number, because 78092221 - 2⁷ = 78092093 is a prime.

It is equal to p_4564615 and since 78092221 and 4564615 have the same sum of digits, it is a Honaker prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (78092227) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 39046110 + 39046111.

It is an arithmetic number, because the mean of its divisors is an integer number (39046111).

Almost surely, 2^78092221 is an apocalyptic number.

It is an amenable number.

78092221 is a deficient number, since it is larger than the sum of its proper divisors (1).

78092221 is an equidigital number, since it uses as much as digits as its factorization.

78092221 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 4032, while the sum is 31.

The square root of 78092221 is about 8836.9803100380. The cubic root of 78092221 is about 427.4341902504.

The spelling of 78092221 in words is "seventy-eight million, ninety-two thousand, two hundred twenty-one".