399003281 has 2 divisors, whose sum is σ = 399003282. Its totient is φ = 399003280.

The previous prime is 399003259. The next prime is 399003289. The reversal of 399003281 is 182300993.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 396647056 + 2356225 = 19916^2 + 1535^2 .

It is a cyclic number.

It is not a de Polignac number, because 399003281 - 2⁶ = 399003217 is a prime.

It is a super-2 number, since 2×399003281² = 318407236497529922, which contains 22 as substring.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (399003289) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 199501640 + 199501641.

It is an arithmetic number, because the mean of its divisors is an integer number (199501641).

Almost surely, 2^399003281 is an apocalyptic number.

It is an amenable number.

399003281 is a deficient number, since it is larger than the sum of its proper divisors (1).

399003281 is an equidigital number, since it uses as much as digits as its factorization.

399003281 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 11664, while the sum is 35.

The square root of 399003281 is about 19975.0664829932. The cubic root of 399003281 is about 736.1938000057.

The spelling of 399003281 in words is "three hundred ninety-nine million, three thousand, two hundred eighty-one".