2051755781 has 2 divisors, whose sum is σ = 2051755782. Its totient is φ = 2051755780.

The previous prime is 2051755759. The next prime is 2051755841. The reversal of 2051755781 is 1875571502.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 1849860100 + 201895681 = 43010^2 + 14209^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-2051755781 is a prime.

It is a super-2 number, since 2×2051755781² = 8419403569733839922, which contains 22 as substring.

It is a Sophie Germain prime.

It is a Curzon number.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (2051755081) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1025877890 + 1025877891.

It is an arithmetic number, because the mean of its divisors is an integer number (1025877891).

Almost surely, 2^2051755781 is an apocalyptic number.

It is an amenable number.

2051755781 is a deficient number, since it is larger than the sum of its proper divisors (1).

2051755781 is an equidigital number, since it uses as much as digits as its factorization.

2051755781 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 98000, while the sum is 41.

The square root of 2051755781 is about 45296.3108983502. The cubic root of 2051755781 is about 1270.6966605766.

The spelling of 2051755781 in words is "two billion, fifty-one million, seven hundred fifty-five thousand, seven hundred eighty-one".