399647 has 2 divisors, whose sum is σ = 399648. Its totient is φ = 399646.

The previous prime is 399643. The next prime is 399667. The reversal of 399647 is 746993.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 399647 - 2² = 399643 is a prime.

It is a Chen prime.

It is a self number, because there is not a number n which added to its sum of digits gives 399647.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (399643) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 199823 + 199824.

It is an arithmetic number, because the mean of its divisors is an integer number (199824).

2³⁹⁹⁶⁴⁷ is an apocalyptic number.

399647 is a deficient number, since it is larger than the sum of its proper divisors (1).

399647 is an equidigital number, since it uses as much as digits as its factorization.

399647 is an evil number, because the sum of its binary digits is even.

The product of its digits is 40824, while the sum is 38.

The square root of 399647 is about 632.1763994329. The cubic root of 399647 is about 73.6589492085.

The spelling of 399647 in words is "three hundred ninety-nine thousand, six hundred forty-seven".