391936849 has 2 divisors, whose sum is σ = 391936850. Its totient is φ = 391936848.

The previous prime is 391936843. The next prime is 391936889. The reversal of 391936849 is 948639193.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 343731600 + 48205249 = 18540^2 + 6943^2 .

It is a cyclic number.

It is not a de Polignac number, because 391936849 - 2¹¹ = 391934801 is a prime.

It is a super-2 number, since 2×391936849² = 307228987208097602, which contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 391936796 and 391936805.

It is not a weakly prime, because it can be changed into another prime (391936843) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 195968424 + 195968425.

It is an arithmetic number, because the mean of its divisors is an integer number (195968425).

Almost surely, 2^391936849 is an apocalyptic number.

It is an amenable number.

391936849 is a deficient number, since it is larger than the sum of its proper divisors (1).

391936849 is an equidigital number, since it uses as much as digits as its factorization.

391936849 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 1259712, while the sum is 52.

The square root of 391936849 is about 19797.3950054041. The cubic root of 391936849 is about 731.8218390751.

The spelling of 391936849 in words is "three hundred ninety-one million, nine hundred thirty-six thousand, eight hundred forty-nine".