1866081686969 has 2 divisors, whose sum is σ = 1866081686970. Its totient is φ = 1866081686968.

The previous prime is 1866081686941. The next prime is 1866081687047. The reversal of 1866081686969 is 9696861806681.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 1866057085369 + 24601600 = 1366037^2 + 4960^2 .

It is a cyclic number.

It is not a de Polignac number, because 1866081686969 - 2²⁰ = 1866080638393 is a prime.

It is a super-2 number, since 2×1866081686969² (a number of 25 digits) contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 1866081686896 and 1866081686905.

It is not a weakly prime, because it can be changed into another prime (1866081686369) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 933040843484 + 933040843485.

It is an arithmetic number, because the mean of its divisors is an integer number (933040843485).

Almost surely, 2^{1866081686969} is an apocalyptic number.

It is an amenable number.

1866081686969 is a deficient number, since it is larger than the sum of its proper divisors (1).

1866081686969 is an equidigital number, since it uses as much as digits as its factorization.

1866081686969 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 322486272, while the sum is 74.

The spelling of 1866081686969 in words is "one trillion, eight hundred sixty-six billion, eighty-one million, six hundred eighty-six thousand, nine hundred sixty-nine".