391618049 has 2 divisors, whose sum is σ = 391618050. Its totient is φ = 391618048.

The previous prime is 391618039. The next prime is 391618061. The reversal of 391618049 is 940816193.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 229310449 + 162307600 = 15143^2 + 12740^2 .

It is a cyclic number.

It is not a de Polignac number, because 391618049 - 2²⁴ = 374840833 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 391617997 and 391618015.

It is not a weakly prime, because it can be changed into another prime (391618039) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 195809024 + 195809025.

It is an arithmetic number, because the mean of its divisors is an integer number (195809025).

Almost surely, 2^391618049 is an apocalyptic number.

It is an amenable number.

391618049 is a deficient number, since it is larger than the sum of its proper divisors (1).

391618049 is an equidigital number, since it uses as much as digits as its factorization.

391618049 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 46656, while the sum is 41.

The square root of 391618049 is about 19789.3418031020. The cubic root of 391618049 is about 731.6233648499.

The spelling of 391618049 in words is "three hundred ninety-one million, six hundred eighteen thousand, forty-nine".