2098778821 has 2 divisors, whose sum is σ = 2098778822. Its totient is φ = 2098778820.

The previous prime is 2098778813. The next prime is 2098778839. The reversal of 2098778821 is 1288778902.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 1498773796 + 600005025 = 38714^2 + 24495^2 .

It is a cyclic number.

It is not a de Polignac number, because 2098778821 - 2³ = 2098778813 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (2098778881) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1049389410 + 1049389411.

It is an arithmetic number, because the mean of its divisors is an integer number (1049389411).

Almost surely, 2^2098778821 is an apocalyptic number.

It is an amenable number.

2098778821 is a deficient number, since it is larger than the sum of its proper divisors (1).

2098778821 is an equidigital number, since it uses as much as digits as its factorization.

2098778821 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 903168, while the sum is 52.

The square root of 2098778821 is about 45812.4308567009. The cubic root of 2098778821 is about 1280.3308920337.

The spelling of 2098778821 in words is "two billion, ninety-eight million, seven hundred seventy-eight thousand, eight hundred twenty-one".