1641790177681 has 2 divisors, whose sum is σ = 1641790177682. Its totient is φ = 1641790177680.

The previous prime is 1641790177679. The next prime is 1641790177693. The reversal of 1641790177681 is 1867710971461.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 1627451312656 + 14338865025 = 1275716^2 + 119745^2 .

It is an emirp because it is prime and its reverse (1867710971461) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 1641790177681 - 2¹ = 1641790177679 is a prime.

It is a super-2 number, since 2×1641790177681² (a number of 25 digits) contains 22 as substring.

Together with 1641790177679, it forms a pair of twin primes.

It is not a weakly prime, because it can be changed into another prime (1641790172681) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 820895088840 + 820895088841.

It is an arithmetic number, because the mean of its divisors is an integer number (820895088841).

Almost surely, 2^{1641790177681} is an apocalyptic number.

It is an amenable number.

1641790177681 is a deficient number, since it is larger than the sum of its proper divisors (1).

1641790177681 is an equidigital number, since it uses as much as digits as its factorization.

1641790177681 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 3556224, while the sum is 58.

The spelling of 1641790177681 in words is "one trillion, six hundred forty-one billion, seven hundred ninety million, one hundred seventy-seven thousand, six hundred eighty-one".