9990561839 has 2 divisors, whose sum is σ = 9990561840. Its totient is φ = 9990561838.

The previous prime is 9990561829. The next prime is 9990561871. The reversal of 9990561839 is 9381650999.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 9990561839 - 2⁸ = 9990561583 is a prime.

It is a super-2 number, since 2×9990561839² (a number of 21 digits) contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (9990561829) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 4995280919 + 4995280920.

It is an arithmetic number, because the mean of its divisors is an integer number (4995280920).

Almost surely, 2^9990561839 is an apocalyptic number.

9990561839 is a deficient number, since it is larger than the sum of its proper divisors (1).

9990561839 is an equidigital number, since it uses as much as digits as its factorization.

9990561839 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 4723920, while the sum is 59.

The square root of 9990561839 is about 99952.7980548819. The cubic root of 9990561839 is about 2153.7566799659.

The spelling of 9990561839 in words is "nine billion, nine hundred ninety million, five hundred sixty-one thousand, eight hundred thirty-nine".