78936721733 has 2 divisors, whose sum is σ = 78936721734. Its totient is φ = 78936721732.

The previous prime is 78936721727. The next prime is 78936721751. The reversal of 78936721733 is 33712763987.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 68454443044 + 10482278689 = 261638^2 + 102383^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-78936721733 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (78936721033) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 39468360866 + 39468360867.

It is an arithmetic number, because the mean of its divisors is an integer number (39468360867).

Almost surely, 2^78936721733 is an apocalyptic number.

It is an amenable number.

78936721733 is a deficient number, since it is larger than the sum of its proper divisors (1).

78936721733 is an equidigital number, since it uses as much as digits as its factorization.

78936721733 is an evil number, because the sum of its binary digits is even.

The product of its digits is 8001504, while the sum is 56.

The spelling of 78936721733 in words is "seventy-eight billion, nine hundred thirty-six million, seven hundred twenty-one thousand, seven hundred thirty-three".