1641797081 has 2 divisors, whose sum is σ = 1641797082. Its totient is φ = 1641797080.

The previous prime is 1641797077. The next prime is 1641797089. The reversal of 1641797081 is 1807971461.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 1309281856 + 332515225 = 36184^2 + 18235^2 .

It is a cyclic number.

It is not a de Polignac number, because 1641797081 - 2² = 1641797077 is a prime.

It is a super-2 number, since 2×1641797081² = 5390995310360241122, which contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (1641797089) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 820898540 + 820898541.

It is an arithmetic number, because the mean of its divisors is an integer number (820898541).

Almost surely, 2^1641797081 is an apocalyptic number.

It is an amenable number.

1641797081 is a deficient number, since it is larger than the sum of its proper divisors (1).

1641797081 is an equidigital number, since it uses as much as digits as its factorization.

1641797081 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 84672, while the sum is 44.

The square root of 1641797081 is about 40519.0952638383. The cubic root of 1641797081 is about 1179.7042927028.

The spelling of 1641797081 in words is "one billion, six hundred forty-one million, seven hundred ninety-seven thousand, eighty-one".