399968969 has 2 divisors, whose sum is σ = 399968970. Its totient is φ = 399968968.

The previous prime is 399968963. The next prime is 399968977. The reversal of 399968969 is 969869993.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 259854400 + 140114569 = 16120^2 + 11837^2 .

It is an emirp because it is prime and its reverse (969869993) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 399968969 - 2⁸ = 399968713 is a prime.

It is a super-2 number, since 2×399968969² = 319950352325845922, which contains 22 as substring.

It is a Chen prime.

It is a junction number, because it is equal to n+sod(n) for n = 399968899 and 399968908.

It is not a weakly prime, because it can be changed into another prime (399968963) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 199984484 + 199984485.

It is an arithmetic number, because the mean of its divisors is an integer number (199984485).

Almost surely, 2^399968969 is an apocalyptic number.

It is an amenable number.

399968969 is a deficient number, since it is larger than the sum of its proper divisors (1).

399968969 is an equidigital number, since it uses as much as digits as its factorization.

399968969 is an evil number, because the sum of its binary digits is even.

The product of its digits is 51018336, while the sum is 68.

The square root of 399968969 is about 19999.2242099537. The cubic root of 399968969 is about 736.7872460385.

The spelling of 399968969 in words is "three hundred ninety-nine million, nine hundred sixty-eight thousand, nine hundred sixty-nine".