1781688068 has 12 divisors (see below), whose sum is σ = 3176783820. Its totient is φ = 874035552.

The previous prime is 1781688067. The next prime is 1781688091. The reversal of 1781688068 is 8608861871.

It is a happy number.

It can be written as a sum of positive squares in 2 ways, for example, as 889351684 + 892336384 = 29822^2 + 29872^2 .

It is a Harshad number since it is a multiple of its sum of digits (53).

It is not an unprimeable number, because it can be changed into a prime (1781688067) 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 in 3 ways as a sum of consecutive naturals, for example, 4201883 + ... + 4202306.

It is an arithmetic number, because the mean of its divisors is an integer number (264731985).

Almost surely, 2^1781688068 is an apocalyptic number.

It is an amenable number.

1781688068 is a deficient number, since it is larger than the sum of its proper divisors (1395095752).

1781688068 is a wasteful number, since it uses less digits than its factorization.

1781688068 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 8404246 (or 8404244 counting only the distinct ones).

The product of its (nonzero) digits is 1032192, while the sum is 53.

The square root of 1781688068 is about 42210.0470030537. The cubic root of 1781688068 is about 1212.3012617622.

The spelling of 1781688068 in words is "one billion, seven hundred eighty-one million, six hundred eighty-eight thousand, sixty-eight".