399619069 has 2 divisors, whose sum is σ = 399619070. Its totient is φ = 399619068.

The previous prime is 399619067. The next prime is 399619079. The reversal of 399619069 is 960916993.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 378108025 + 21511044 = 19445^2 + 4638^2 .

It is a cyclic number.

It is not a de Polignac number, because 399619069 - 2¹ = 399619067 is a prime.

It is a super-2 number, since 2×399619069² = 319390800616853522, which contains 22 as substring.

Together with 399619067, it forms a pair of twin primes.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (399619061) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 199809534 + 199809535.

It is an arithmetic number, because the mean of its divisors is an integer number (199809535).

Almost surely, 2^399619069 is an apocalyptic number.

It is an amenable number.

399619069 is a deficient number, since it is larger than the sum of its proper divisors (1).

399619069 is an equidigital number, since it uses as much as digits as its factorization.

399619069 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 708588, while the sum is 52.

The square root of 399619069 is about 19990.4744566006. The cubic root of 399619069 is about 736.5723318072.

The spelling of 399619069 in words is "three hundred ninety-nine million, six hundred nineteen thousand, sixty-nine".