409278109 has 2 divisors, whose sum is σ = 409278110. Its totient is φ = 409278108.

The previous prime is 409278091. The next prime is 409278157. The reversal of 409278109 is 901872904.

Together with previous prime (409278091) it forms an Ormiston pair, because they use the same digits, order apart.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 232654009 + 176624100 = 15253^2 + 13290^2 .

It is a cyclic number.

It is not a de Polignac number, because 409278109 - 2⁹ = 409277597 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (409278509) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 204639054 + 204639055.

It is an arithmetic number, because the mean of its divisors is an integer number (204639055).

Almost surely, 2^409278109 is an apocalyptic number.

It is an amenable number.

409278109 is a deficient number, since it is larger than the sum of its proper divisors (1).

409278109 is an equidigital number, since it uses as much as digits as its factorization.

409278109 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 36288, while the sum is 40.

The square root of 409278109 is about 20230.6230502177. The cubic root of 409278109 is about 742.4596199892.

The spelling of 409278109 in words is "four hundred nine million, two hundred seventy-eight thousand, one hundred nine".