39806609 has 2 divisors, whose sum is σ = 39806610. Its totient is φ = 39806608.

The previous prime is 39806597. The next prime is 39806617. The reversal of 39806609 is 90660893.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 37246609 + 2560000 = 6103^2 + 1600^2 .

It is an emirp because it is prime and its reverse (90660893) is a distict prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-39806609 is a prime.

It is a super-2 number, since 2×39806609² = 3169132240157762, which contains 22 as substring.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (39806699) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 19903304 + 19903305.

It is an arithmetic number, because the mean of its divisors is an integer number (19903305).

Almost surely, 2^39806609 is an apocalyptic number.

It is an amenable number.

39806609 is a deficient number, since it is larger than the sum of its proper divisors (1).

39806609 is an equidigital number, since it uses as much as digits as its factorization.

39806609 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 69984, while the sum is 41.

The square root of 39806609 is about 6309.2478949555. The cubic root of 39806609 is about 341.4431421053.

The spelling of 39806609 in words is "thirty-nine million, eight hundred six thousand, six hundred nine".