39899813 has 2 divisors, whose sum is σ = 39899814. Its totient is φ = 39899812.

The previous prime is 39899809. The next prime is 39899903. The reversal of 39899813 is 31899893.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 35307364 + 4592449 = 5942^2 + 2143^2 .

It is an emirp because it is prime and its reverse (31899893) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 39899813 - 2² = 39899809 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (39899803) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 19949906 + 19949907.

It is an arithmetic number, because the mean of its divisors is an integer number (19949907).

Almost surely, 2^39899813 is an apocalyptic number.

It is an amenable number.

39899813 is a deficient number, since it is larger than the sum of its proper divisors (1).

39899813 is an equidigital number, since it uses as much as digits as its factorization.

39899813 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 419904, while the sum is 50.

The square root of 39899813 is about 6316.6298767618. The cubic root of 39899813 is about 341.7094216837.

The spelling of 39899813 in words is "thirty-nine million, eight hundred ninety-nine thousand, eight hundred thirteen".