2991682781 has 2 divisors, whose sum is σ = 2991682782. Its totient is φ = 2991682780.

The previous prime is 2991682777. The next prime is 2991682787. The reversal of 2991682781 is 1872861992.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 2124380281 + 867302500 = 46091^2 + 29450^2 .

It is a cyclic number.

It is not a de Polignac number, because 2991682781 - 2² = 2991682777 is a prime.

It is a super-2 number, since 2×2991682781² = 17900331724263787922, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (2991682787) 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, 1495841390 + 1495841391.

It is an arithmetic number, because the mean of its divisors is an integer number (1495841391).

Almost surely, 2^2991682781 is an apocalyptic number.

It is an amenable number.

2991682781 is a deficient number, since it is larger than the sum of its proper divisors (1).

2991682781 is an equidigital number, since it uses as much as digits as its factorization.

2991682781 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 870912, while the sum is 53.

The square root of 2991682781 is about 54696.2775790090. The cubic root of 2991682781 is about 1440.9155027400.

The spelling of 2991682781 in words is "two billion, nine hundred ninety-one million, six hundred eighty-two thousand, seven hundred eighty-one".