399822649 has 2 divisors, whose sum is σ = 399822650. Its totient is φ = 399822648.

The previous prime is 399822613. The next prime is 399822667. The reversal of 399822649 is 946228993.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 336906025 + 62916624 = 18355^2 + 7932^2 .

It is a cyclic number.

It is not a de Polignac number, because 399822649 - 2¹¹ = 399820601 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 399822596 and 399822605.

It is not a weakly prime, because it can be changed into another prime (399826649) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 199911324 + 199911325.

It is an arithmetic number, because the mean of its divisors is an integer number (199911325).

Almost surely, 2^399822649 is an apocalyptic number.

It is an amenable number.

399822649 is a deficient number, since it is larger than the sum of its proper divisors (1).

399822649 is an equidigital number, since it uses as much as digits as its factorization.

399822649 is an evil number, because the sum of its binary digits is even.

The product of its digits is 1679616, while the sum is 52.

The square root of 399822649 is about 19995.5657334320. The cubic root of 399822649 is about 736.6973891853.

The spelling of 399822649 in words is "three hundred ninety-nine million, eight hundred twenty-two thousand, six hundred forty-nine".