78779017 has 2 divisors, whose sum is σ = 78779018. Its totient is φ = 78779016.

The previous prime is 78779011. The next prime is 78779023. The reversal of 78779017 is 71097787.

It is a balanced prime because it is at equal distance from previous prime (78779011) and next prime (78779023).

It can be written as a sum of positive squares in only one way, i.e., 57471561 + 21307456 = 7581^2 + 4616^2 .

It is a cyclic number.

It is not a de Polignac number, because 78779017 - 2³ = 78779009 is a prime.

It is a super-2 number, since 2×78779017² = 12412267038972578, which contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (78779011) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 39389508 + 39389509.

It is an arithmetic number, because the mean of its divisors is an integer number (39389509).

Almost surely, 2^78779017 is an apocalyptic number.

It is an amenable number.

78779017 is a deficient number, since it is larger than the sum of its proper divisors (1).

78779017 is an equidigital number, since it uses as much as digits as its factorization.

78779017 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 172872, while the sum is 46.

The square root of 78779017 is about 8875.7544468062. The cubic root of 78779017 is about 428.6835835095.

The spelling of 78779017 in words is "seventy-eight million, seven hundred seventy-nine thousand, seventeen".