1995759781 has 2 divisors, whose sum is σ = 1995759782. Its totient is φ = 1995759780.

The previous prime is 1995759769. The next prime is 1995759811. The reversal of 1995759781 is 1879575991.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 1746404100 + 249355681 = 41790^2 + 15791^2 .

It is a cyclic number.

It is not a de Polignac number, because 1995759781 - 2⁷ = 1995759653 is a prime.

It is a super-2 number, since 2×1995759781² = 7966114206914335922, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1995759751) 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, 997879890 + 997879891.

It is an arithmetic number, because the mean of its divisors is an integer number (997879891).

Almost surely, 2^1995759781 is an apocalyptic number.

It is an amenable number.

1995759781 is a deficient number, since it is larger than the sum of its proper divisors (1).

1995759781 is an equidigital number, since it uses as much as digits as its factorization.

1995759781 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 7144200, while the sum is 61.

The square root of 1995759781 is about 44673.9273066517. The cubic root of 1995759781 is about 1259.0300297154.

The spelling of 1995759781 in words is "one billion, nine hundred ninety-five million, seven hundred fifty-nine thousand, seven hundred eighty-one".