68008021 has 2 divisors, whose sum is σ = 68008022. Its totient is φ = 68008020.

The previous prime is 68008009. The next prime is 68008037. The reversal of 68008021 is 12080086.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 51279921 + 16728100 = 7161^2 + 4090^2 .

It is a cyclic number.

It is not a de Polignac number, because 68008021 - 2¹³ = 67999829 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (68008081) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 34004010 + 34004011.

It is an arithmetic number, because the mean of its divisors is an integer number (34004011).

Almost surely, 2^68008021 is an apocalyptic number.

It is an amenable number.

68008021 is a deficient number, since it is larger than the sum of its proper divisors (1).

68008021 is an equidigital number, since it uses as much as digits as its factorization.

68008021 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 768, while the sum is 25.

The square root of 68008021 is about 8246.6975814565. The cubic root of 68008021 is about 408.1815580684.

The spelling of 68008021 in words is "sixty-eight million, eight thousand, twenty-one".