78429089 has 2 divisors, whose sum is σ = 78429090. Its totient is φ = 78429088.

The previous prime is 78429077. The next prime is 78429133. The reversal of 78429089 is 98092487.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 67486225 + 10942864 = 8215^2 + 3308^2 .

It is an emirp because it is prime and its reverse (98092487) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 78429089 - 2⁴ = 78429073 is a prime.

It is a super-2 number, since 2×78429089² = 12302244002739842, which contains 22 as substring.

It is a Sophie Germain prime.

It is a Curzon number.

It is not a weakly prime, because it can be changed into another prime (78429019) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 39214544 + 39214545.

It is an arithmetic number, because the mean of its divisors is an integer number (39214545).

Almost surely, 2^78429089 is an apocalyptic number.

It is an amenable number.

78429089 is a deficient number, since it is larger than the sum of its proper divisors (1).

78429089 is an equidigital number, since it uses as much as digits as its factorization.

78429089 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 290304, while the sum is 47.

The square root of 78429089 is about 8856.0199299685. The cubic root of 78429089 is about 428.0479191260.

The spelling of 78429089 in words is "seventy-eight million, four hundred twenty-nine thousand, eighty-nine".