2781801509 has 2 divisors, whose sum is σ = 2781801510. Its totient is φ = 2781801508.

The previous prime is 2781801487. The next prime is 2781801551. The reversal of 2781801509 is 9051081872.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 2527877284 + 253924225 = 50278^2 + 15935^2 .

It is a cyclic number.

It is not a de Polignac number, because 2781801509 - 2²⁴ = 2765024293 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (2781851509) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1390900754 + 1390900755.

It is an arithmetic number, because the mean of its divisors is an integer number (1390900755).

Almost surely, 2^2781801509 is an apocalyptic number.

It is an amenable number.

2781801509 is a deficient number, since it is larger than the sum of its proper divisors (1).

2781801509 is an equidigital number, since it uses as much as digits as its factorization.

2781801509 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 40320, while the sum is 41.

The square root of 2781801509 is about 52742.7863219227. The cubic root of 2781801509 is about 1406.3995306370.

The spelling of 2781801509 in words is "two billion, seven hundred eighty-one million, eight hundred one thousand, five hundred nine".