68389021 has 2 divisors, whose sum is σ = 68389022. Its totient is φ = 68389020.

The previous prime is 68389001. The next prime is 68389031. The reversal of 68389021 is 12098386.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 63920025 + 4468996 = 7995^2 + 2114^2 .

It is a cyclic number.

It is not a de Polignac number, because 68389021 - 2¹⁷ = 68257949 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (68389001) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 34194510 + 34194511.

It is an arithmetic number, because the mean of its divisors is an integer number (34194511).

Almost surely, 2^68389021 is an apocalyptic number.

It is an amenable number.

68389021 is a deficient number, since it is larger than the sum of its proper divisors (1).

68389021 is an equidigital number, since it uses as much as digits as its factorization.

68389021 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 20736, while the sum is 37.

The square root of 68389021 is about 8269.7654743046. The cubic root of 68389021 is about 408.9423882123.

The spelling of 68389021 in words is "sixty-eight million, three hundred eighty-nine thousand, twenty-one".