1683904250921 has 2 divisors, whose sum is σ = 1683904250922. Its totient is φ = 1683904250920.

The previous prime is 1683904250891. The next prime is 1683904250929. The reversal of 1683904250921 is 1290524093861.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 1395788659225 + 288115591696 = 1181435^2 + 536764^2 .

It is a cyclic number.

It is not a de Polignac number, because 1683904250921 - 2¹⁸ = 1683903988777 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 1683904250921.

It is not a weakly prime, because it can be changed into another prime (1683904250929) 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, 841952125460 + 841952125461.

It is an arithmetic number, because the mean of its divisors is an integer number (841952125461).

Almost surely, 2^{1683904250921} is an apocalyptic number.

It is an amenable number.

1683904250921 is a deficient number, since it is larger than the sum of its proper divisors (1).

1683904250921 is an equidigital number, since it uses as much as digits as its factorization.

1683904250921 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 933120, while the sum is 50.

The spelling of 1683904250921 in words is "one trillion, six hundred eighty-three billion, nine hundred four million, two hundred fifty thousand, nine hundred twenty-one".