1868500365661 has 2 divisors, whose sum is σ = 1868500365662. Its totient is φ = 1868500365660.

The previous prime is 1868500365643. The next prime is 1868500365673. The reversal of 1868500365661 is 1665630058681.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 1674257432761 + 194242932900 = 1293931^2 + 440730^2 .

It is a cyclic number.

It is not a de Polignac number, because 1868500365661 - 2¹³ = 1868500357469 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1868500365631) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 934250182830 + 934250182831.

It is an arithmetic number, because the mean of its divisors is an integer number (934250182831).

Almost surely, 2^{1868500365661} is an apocalyptic number.

It is an amenable number.

1868500365661 is a deficient number, since it is larger than the sum of its proper divisors (1).

1868500365661 is an equidigital number, since it uses as much as digits as its factorization.

1868500365661 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 6220800, while the sum is 55.

The spelling of 1868500365661 in words is "one trillion, eight hundred sixty-eight billion, five hundred million, three hundred sixty-five thousand, six hundred sixty-one".