1649856617 has 2 divisors, whose sum is σ = 1649856618. Its totient is φ = 1649856616.

The previous prime is 1649856601. The next prime is 1649856623. The reversal of 1649856617 is 7166589461.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 1381683241 + 268173376 = 37171^2 + 16376^2 .

It is a cyclic number.

It is not a de Polignac number, because 1649856617 - 2⁴ = 1649856601 is a prime.

It is a super-3 number, since 3×1649856617³ (a number of 29 digits) contains 333 as substring.

It is not a weakly prime, because it can be changed into another prime (1649856517) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 824928308 + 824928309.

It is an arithmetic number, because the mean of its divisors is an integer number (824928309).

Almost surely, 2^1649856617 is an apocalyptic number.

It is an amenable number.

1649856617 is a deficient number, since it is larger than the sum of its proper divisors (1).

1649856617 is an equidigital number, since it uses as much as digits as its factorization.

1649856617 is an evil number, because the sum of its binary digits is even.

The product of its digits is 2177280, while the sum is 53.

The square root of 1649856617 is about 40618.4270621106. The cubic root of 1649856617 is about 1181.6315210355.

The spelling of 1649856617 in words is "one billion, six hundred forty-nine million, eight hundred fifty-six thousand, six hundred seventeen".