399687241 has 2 divisors, whose sum is σ = 399687242. Its totient is φ = 399687240.

The previous prime is 399687203. The next prime is 399687313. The reversal of 399687241 is 142786993.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 398840841 + 846400 = 19971^2 + 920^2 .

It is a cyclic number.

It is not a de Polignac number, because 399687241 - 2¹⁵ = 399654473 is a prime.

It is a super-4 number, since 4×399687241⁴ (a number of 36 digits) contains 4444 as substring.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (399687641) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 199843620 + 199843621.

It is an arithmetic number, because the mean of its divisors is an integer number (199843621).

Almost surely, 2^399687241 is an apocalyptic number.

It is an amenable number.

399687241 is a deficient number, since it is larger than the sum of its proper divisors (1).

399687241 is an equidigital number, since it uses as much as digits as its factorization.

399687241 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 653184, while the sum is 49.

The square root of 399687241 is about 19992.1794959929. The cubic root of 399687241 is about 736.6142139877.

The spelling of 399687241 in words is "three hundred ninety-nine million, six hundred eighty-seven thousand, two hundred forty-one".