78073813 has 2 divisors, whose sum is σ = 78073814. Its totient is φ = 78073812.

The previous prime is 78073789. The next prime is 78073817. The reversal of 78073813 is 31837087.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 77845329 + 228484 = 8823^2 + 478^2 .

It is a cyclic number.

It is not a de Polignac number, because 78073813 - 2²¹ = 75976661 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (78073817) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 39036906 + 39036907.

It is an arithmetic number, because the mean of its divisors is an integer number (39036907).

Almost surely, 2^78073813 is an apocalyptic number.

It is an amenable number.

78073813 is a deficient number, since it is larger than the sum of its proper divisors (1).

78073813 is an equidigital number, since it uses as much as digits as its factorization.

78073813 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 28224, while the sum is 37.

The square root of 78073813 is about 8835.9387164013. The cubic root of 78073813 is about 427.4006024966.

The spelling of 78073813 in words is "seventy-eight million, seventy-three thousand, eight hundred thirteen".