1791661642481 has 2 divisors, whose sum is σ = 1791661642482. Its totient is φ = 1791661642480.

The previous prime is 1791661642451. The next prime is 1791661642493. The reversal of 1791661642481 is 1842461661971.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 1713755901025 + 77905741456 = 1309105^2 + 279116^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1791661642481 is a prime.

It is a super-2 number, since 2×1791661642481² (a number of 25 digits) contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (1791661642451) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 895830821240 + 895830821241.

It is an arithmetic number, because the mean of its divisors is an integer number (895830821241).

Almost surely, 2^{1791661642481} is an apocalyptic number.

It is an amenable number.

1791661642481 is a deficient number, since it is larger than the sum of its proper divisors (1).

1791661642481 is an equidigital number, since it uses as much as digits as its factorization.

1791661642481 is an evil number, because the sum of its binary digits is even.

The product of its digits is 3483648, while the sum is 56.

The spelling of 1791661642481 in words is "one trillion, seven hundred ninety-one billion, six hundred sixty-one million, six hundred forty-two thousand, four hundred eighty-one".