1861780551227 has 2 divisors, whose sum is σ = 1861780551228. Its totient is φ = 1861780551226.

The previous prime is 1861780551181. The next prime is 1861780551233. The reversal of 1861780551227 is 7221550871681.

It is a strong prime.

It is an emirp because it is prime and its reverse (7221550871681) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 1861780551227 - 2²⁴ = 1861763774011 is a prime.

It is a super-2 number, since 2×1861780551227² (a number of 25 digits) contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (1861780571227) 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, 930890275613 + 930890275614.

It is an arithmetic number, because the mean of its divisors is an integer number (930890275614).

Almost surely, 2^{1861780551227} is an apocalyptic number.

1861780551227 is a deficient number, since it is larger than the sum of its proper divisors (1).

1861780551227 is an equidigital number, since it uses as much as digits as its factorization.

1861780551227 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 1881600, while the sum is 53.

The spelling of 1861780551227 in words is "one trillion, eight hundred sixty-one billion, seven hundred eighty million, five hundred fifty-one thousand, two hundred twenty-seven".