70778861 has 2 divisors, whose sum is σ = 70778862. Its totient is φ = 70778860.

The previous prime is 70778839. The next prime is 70778893. The reversal of 70778861 is 16887707.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 68376361 + 2402500 = 8269^2 + 1550^2 .

It is an emirp because it is prime and its reverse (16887707) is a distict prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-70778861 is a prime.

It is a Sophie Germain prime.

It is a Chen prime.

It is a Curzon number.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (70778801) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 35389430 + 35389431.

It is an arithmetic number, because the mean of its divisors is an integer number (35389431).

Almost surely, 2^70778861 is an apocalyptic number.

It is an amenable number.

70778861 is a deficient number, since it is larger than the sum of its proper divisors (1).

70778861 is an equidigital number, since it uses as much as digits as its factorization.

70778861 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 131712, while the sum is 44.

The square root of 70778861 is about 8413.0173540770. The cubic root of 70778861 is about 413.6514234724.

The spelling of 70778861 in words is "seventy million, seven hundred seventy-eight thousand, eight hundred sixty-one".