78317761 has 2 divisors, whose sum is σ = 78317762. Its totient is φ = 78317760.

The previous prime is 78317747. The next prime is 78317779. The reversal of 78317761 is 16771387.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 65934400 + 12383361 = 8120^2 + 3519^2 .

It is a cyclic number.

It is not a de Polignac number, because 78317761 - 2⁷ = 78317633 is a prime.

It is a super-2 number, since 2×78317761² = 12267343376106242, which contains 22 as substring.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (78317711) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 39158880 + 39158881.

It is an arithmetic number, because the mean of its divisors is an integer number (39158881).

Almost surely, 2^78317761 is an apocalyptic number.

It is an amenable number.

78317761 is a deficient number, since it is larger than the sum of its proper divisors (1).

78317761 is an equidigital number, since it uses as much as digits as its factorization.

78317761 is an evil number, because the sum of its binary digits is even.

The product of its digits is 49392, while the sum is 40.

The square root of 78317761 is about 8849.7322558369. The cubic root of 78317761 is about 427.8452890182.

The spelling of 78317761 in words is "seventy-eight million, three hundred seventeen thousand, seven hundred sixty-one".