78943729 has 2 divisors, whose sum is σ = 78943730. Its totient is φ = 78943728.

The previous prime is 78943723. The next prime is 78943757. The reversal of 78943729 is 92734987.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 77792400 + 1151329 = 8820^2 + 1073^2 .

It is a cyclic number.

It is not a de Polignac number, because 78943729 - 2²¹ = 76846577 is a prime.

It is a super-2 number, since 2×78943729² = 12464224696850882, which contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (78943723) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 39471864 + 39471865.

It is an arithmetic number, because the mean of its divisors is an integer number (39471865).

Almost surely, 2^78943729 is an apocalyptic number.

It is an amenable number.

78943729 is a deficient number, since it is larger than the sum of its proper divisors (1).

78943729 is an equidigital number, since it uses as much as digits as its factorization.

78943729 is an evil number, because the sum of its binary digits is even.

The product of its digits is 762048, while the sum is 49.

The square root of 78943729 is about 8885.0283623633. The cubic root of 78943729 is about 428.9821409170.

The spelling of 78943729 in words is "seventy-eight million, nine hundred forty-three thousand, seven hundred twenty-nine".