1819777833781 has 2 divisors, whose sum is σ = 1819777833782. Its totient is φ = 1819777833780.

The previous prime is 1819777833751. The next prime is 1819777833791. The reversal of 1819777833781 is 1873387779181.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 1795023846225 + 24753987556 = 1339785^2 + 157334^2 .

It is a cyclic number.

It is not a de Polignac number, because 1819777833781 - 2¹³ = 1819777825589 is a prime.

It is a super-2 number, since 2×1819777833781² (a number of 25 digits) contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 1819777833781.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1819777833701) 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, 909888916890 + 909888916891.

It is an arithmetic number, because the mean of its divisors is an integer number (909888916891).

Almost surely, 2^{1819777833781} is an apocalyptic number.

It is an amenable number.

1819777833781 is a deficient number, since it is larger than the sum of its proper divisors (1).

1819777833781 is an equidigital number, since it uses as much as digits as its factorization.

1819777833781 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 99574272, while the sum is 70.

The spelling of 1819777833781 in words is "one trillion, eight hundred nineteen billion, seven hundred seventy-seven million, eight hundred thirty-three thousand, seven hundred eighty-one".