1890781687049 has 2 divisors, whose sum is σ = 1890781687050. Its totient is φ = 1890781687048.

The previous prime is 1890781687037. The next prime is 1890781687117. The reversal of 1890781687049 is 9407861870981.

It is an a-pointer prime, because the next prime (1890781687117) can be obtained adding 1890781687049 to its sum of digits (68).

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 1277272927225 + 613508759824 = 1130165^2 + 783268^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1890781687049 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 1890781687049.

It is not a weakly prime, because it can be changed into another prime (1890781287049) 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, 945390843524 + 945390843525.

It is an arithmetic number, because the mean of its divisors is an integer number (945390843525).

Almost surely, 2^{1890781687049} is an apocalyptic number.

It is an amenable number.

1890781687049 is a deficient number, since it is larger than the sum of its proper divisors (1).

1890781687049 is an equidigital number, since it uses as much as digits as its factorization.

1890781687049 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 48771072, while the sum is 68.

The spelling of 1890781687049 in words is "one trillion, eight hundred ninety billion, seven hundred eighty-one million, six hundred eighty-seven thousand, forty-nine".