649872857 has 2 divisors, whose sum is σ = 649872858. Its totient is φ = 649872856.

The previous prime is 649872829. The next prime is 649872893. The reversal of 649872857 is 758278946.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 644093641 + 5779216 = 25379^2 + 2404^2 .

It is a cyclic number.

It is not a de Polignac number, because 649872857 - 2⁶ = 649872793 is a prime.

It is a super-3 number, since 3×649872857³ (a number of 27 digits) contains 333 as substring.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (649872557) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 324936428 + 324936429.

It is an arithmetic number, because the mean of its divisors is an integer number (324936429).

Almost surely, 2^649872857 is an apocalyptic number.

It is an amenable number.

649872857 is a deficient number, since it is larger than the sum of its proper divisors (1).

649872857 is an equidigital number, since it uses as much as digits as its factorization.

649872857 is an evil number, because the sum of its binary digits is even.

The product of its digits is 6773760, while the sum is 56.

The square root of 649872857 is about 25492.6039666410. The cubic root of 649872857 is about 866.1826215356.

The spelling of 649872857 in words is "six hundred forty-nine million, eight hundred seventy-two thousand, eight hundred fifty-seven".