1866481680829 has 2 divisors, whose sum is σ = 1866481680830. Its totient is φ = 1866481680828.

The previous prime is 1866481680809. The next prime is 1866481680851. The reversal of 1866481680829 is 9280861846681.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 1838662776729 + 27818904100 = 1355973^2 + 166790^2 .

It is an emirp because it is prime and its reverse (9280861846681) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 1866481680829 - 2²³ = 1866473292221 is a prime.

It is a super-2 number, since 2×1866481680829² (a number of 25 digits) contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1866481680809) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 933240840414 + 933240840415.

It is an arithmetic number, because the mean of its divisors is an integer number (933240840415).

Almost surely, 2^{1866481680829} is an apocalyptic number.

It is an amenable number.

1866481680829 is a deficient number, since it is larger than the sum of its proper divisors (1).

1866481680829 is an equidigital number, since it uses as much as digits as its factorization.

1866481680829 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 63700992, while the sum is 67.

The spelling of 1866481680829 in words is "one trillion, eight hundred sixty-six billion, four hundred eighty-one million, six hundred eighty thousand, eight hundred twenty-nine".