10491990857 has 2 divisors, whose sum is σ = 10491990858. Its totient is φ = 10491990856.

The previous prime is 10491990853. The next prime is 10491990913. The reversal of 10491990857 is 75809919401.

10491990857 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 5909919376 + 4582071481 = 76876^2 + 67691^2 .

It is a cyclic number.

It is not a de Polignac number, because 10491990857 - 2² = 10491990853 is a prime.

It is a super-2 number, since 2×10491990857² (a number of 21 digits) contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 10491990799 and 10491990808.

It is not a weakly prime, because it can be changed into another prime (10491990851) 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, 5245995428 + 5245995429.

It is an arithmetic number, because the mean of its divisors is an integer number (5245995429).

Almost surely, 2^10491990857 is an apocalyptic number.

It is an amenable number.

10491990857 is a deficient number, since it is larger than the sum of its proper divisors (1).

10491990857 is an equidigital number, since it uses as much as digits as its factorization.

10491990857 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 816480, while the sum is 53.

The spelling of 10491990857 in words is "ten billion, four hundred ninety-one million, nine hundred ninety thousand, eight hundred fifty-seven".