1890881281 has 2 divisors, whose sum is σ = 1890881282. Its totient is φ = 1890881280.

The previous prime is 1890881257. The next prime is 1890881323. The reversal of 1890881281 is 1821880981.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 1890510400 + 370881 = 43480^2 + 609^2 .

It is an emirp because it is prime and its reverse (1821880981) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 1890881281 - 2⁵ = 1890881249 is a prime.

It is a super-3 number, since 3×1890881281³ (a number of 29 digits) contains 333 as substring. Note that it is a super-d number also for d = 2.

It is not a weakly prime, because it can be changed into another prime (1890881081) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 945440640 + 945440641.

It is an arithmetic number, because the mean of its divisors is an integer number (945440641).

Almost surely, 2^1890881281 is an apocalyptic number.

It is an amenable number.

1890881281 is a deficient number, since it is larger than the sum of its proper divisors (1).

1890881281 is an equidigital number, since it uses as much as digits as its factorization.

1890881281 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 73728, while the sum is 46.

The square root of 1890881281 is about 43484.2647517467. The cubic root of 1890881281 is about 1236.5777299456.

The spelling of 1890881281 in words is "one billion, eight hundred ninety million, eight hundred eighty-one thousand, two hundred eighty-one".