1851766477409 has 2 divisors, whose sum is σ = 1851766477410. Its totient is φ = 1851766477408.

The previous prime is 1851766477349. The next prime is 1851766477487. The reversal of 1851766477409 is 9047746671581.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 1074442121809 + 777324355600 = 1036553^2 + 881660^2 .

It is a cyclic number.

It is not a de Polignac number, because 1851766477409 - 2¹² = 1851766473313 is a prime.

It is not a weakly prime, because it can be changed into another prime (1851766476409) 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, 925883238704 + 925883238705.

It is an arithmetic number, because the mean of its divisors is an integer number (925883238705).

Almost surely, 2^{1851766477409} is an apocalyptic number.

It is an amenable number.

1851766477409 is a deficient number, since it is larger than the sum of its proper divisors (1).

1851766477409 is an equidigital number, since it uses as much as digits as its factorization.

1851766477409 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 71124480, while the sum is 65.

The spelling of 1851766477409 in words is "one trillion, eight hundred fifty-one billion, seven hundred sixty-six million, four hundred seventy-seven thousand, four hundred nine".