78068821 has 2 divisors, whose sum is σ = 78068822. Its totient is φ = 78068820.

The previous prime is 78068813. The next prime is 78068839. The reversal of 78068821 is 12886087.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 69722500 + 8346321 = 8350^2 + 2889^2 .

It is a cyclic number.

It is not a de Polignac number, because 78068821 - 2³ = 78068813 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (78068621) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 39034410 + 39034411.

It is an arithmetic number, because the mean of its divisors is an integer number (39034411).

Almost surely, 2^78068821 is an apocalyptic number.

It is an amenable number.

78068821 is a deficient number, since it is larger than the sum of its proper divisors (1).

78068821 is an equidigital number, since it uses as much as digits as its factorization.

78068821 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 43008, while the sum is 40.

The square root of 78068821 is about 8835.6562291660. The cubic root of 78068821 is about 427.3914930432.

The spelling of 78068821 in words is "seventy-eight million, sixty-eight thousand, eight hundred twenty-one".