1981058777 has 2 divisors, whose sum is σ = 1981058778. Its totient is φ = 1981058776.

The previous prime is 1981058767. The next prime is 1981058797. The reversal of 1981058777 is 7778501891.

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., 1674773776 + 306285001 = 40924^2 + 17501^2 .

It is an emirp because it is prime and its reverse (7778501891) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 1981058777 - 2³⁰ = 907316953 is a prime.

It is not a weakly prime, because it can be changed into another prime (1981058767) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 990529388 + 990529389.

It is an arithmetic number, because the mean of its divisors is an integer number (990529389).

Almost surely, 2^1981058777 is an apocalyptic number.

It is an amenable number.

1981058777 is a deficient number, since it is larger than the sum of its proper divisors (1).

1981058777 is an equidigital number, since it uses as much as digits as its factorization.

1981058777 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 987840, while the sum is 53.

The square root of 1981058777 is about 44509.0864543410. The cubic root of 1981058777 is about 1255.9310196558.

It can be divided in two parts, 19810 and 58777, that added together give a palindrome (78587).

The spelling of 1981058777 in words is "one billion, nine hundred eighty-one million, fifty-eight thousand, seven hundred seventy-seven".