3999550561 has 2 divisors, whose sum is σ = 3999550562. Its totient is φ = 3999550560.

The previous prime is 3999550553. The next prime is 3999550567. The reversal of 3999550561 is 1650559993.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 2534115600 + 1465434961 = 50340^2 + 38281^2 .

It is an emirp because it is prime and its reverse (1650559993) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 3999550561 - 2³ = 3999550553 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 3999550499 and 3999550508.

It is not a weakly prime, because it can be changed into another prime (3999550567) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1999775280 + 1999775281.

It is an arithmetic number, because the mean of its divisors is an integer number (1999775281).

Almost surely, 2^3999550561 is an apocalyptic number.

It is an amenable number.

3999550561 is a deficient number, since it is larger than the sum of its proper divisors (1).

3999550561 is an equidigital number, since it uses as much as digits as its factorization.

3999550561 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 1640250, while the sum is 52.

The square root of 3999550561 is about 63241.9999762816. Note that the first 4 decimals coincide. The cubic root of 3999550561 is about 1587.3415964129.

The spelling of 3999550561 in words is "three billion, nine hundred ninety-nine million, five hundred fifty thousand, five hundred sixty-one".