2099950781 has 2 divisors, whose sum is σ = 2099950782. Its totient is φ = 2099950780.

The previous prime is 2099950771. The next prime is 2099950861. The reversal of 2099950781 is 1870599902.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 1824058681 + 275892100 = 42709^2 + 16610^2 .

It is a cyclic number.

It is not a de Polignac number, because 2099950781 - 2¹⁰ = 2099949757 is a prime.

It is a super-2 number, since 2×2099950781² = 8819586565245019922, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (2099950771) 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, 1049975390 + 1049975391.

It is an arithmetic number, because the mean of its divisors is an integer number (1049975391).

Almost surely, 2^2099950781 is an apocalyptic number.

It is an amenable number.

2099950781 is a deficient number, since it is larger than the sum of its proper divisors (1).

2099950781 is an equidigital number, since it uses as much as digits as its factorization.

2099950781 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 408240, while the sum is 50.

The square root of 2099950781 is about 45825.2199230947. The cubic root of 2099950781 is about 1280.5691603338.

The spelling of 2099950781 in words is "two billion, ninety-nine million, nine hundred fifty thousand, seven hundred eighty-one".