78222539 has 2 divisors, whose sum is σ = 78222540. Its totient is φ = 78222538.

The previous prime is 78222511. The next prime is 78222577. The reversal of 78222539 is 93522287.

It is an a-pointer prime, because the next prime (78222577) can be obtained adding 78222539 to its sum of digits (38).

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 78222539 - 2⁸ = 78222283 is a prime.

It is a super-2 number, since 2×78222539² = 12237531215213042, which contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (78222509) 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, 39111269 + 39111270.

It is an arithmetic number, because the mean of its divisors is an integer number (39111270).

Almost surely, 2^78222539 is an apocalyptic number.

78222539 is a deficient number, since it is larger than the sum of its proper divisors (1).

78222539 is an equidigital number, since it uses as much as digits as its factorization.

78222539 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 60480, while the sum is 38.

The square root of 78222539 is about 8844.3506827805. The cubic root of 78222539 is about 427.6718213143.

The spelling of 78222539 in words is "seventy-eight million, two hundred twenty-two thousand, five hundred thirty-nine".