78227609 has 2 divisors, whose sum is σ = 78227610. Its totient is φ = 78227608.

The previous prime is 78227581. The next prime is 78227627. The reversal of 78227609 is 90672287.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 44622400 + 33605209 = 6680^2 + 5797^2 .

It is an emirp because it is prime and its reverse (90672287) is a distict prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-78227609 is a prime.

It is a super-2 number, since 2×78227609² = 12239117619713762, which contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (78227689) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 39113804 + 39113805.

It is an arithmetic number, because the mean of its divisors is an integer number (39113805).

Almost surely, 2^78227609 is an apocalyptic number.

It is an amenable number.

78227609 is a deficient number, since it is larger than the sum of its proper divisors (1).

78227609 is an equidigital number, since it uses as much as digits as its factorization.

78227609 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 84672, while the sum is 41.

The square root of 78227609 is about 8844.6373017778. The cubic root of 78227609 is about 427.6810609756.

The spelling of 78227609 in words is "seventy-eight million, two hundred twenty-seven thousand, six hundred nine".