70687709 has 2 divisors, whose sum is σ = 70687710. Its totient is φ = 70687708.

The previous prime is 70687681. The next prime is 70687711. The reversal of 70687709 is 90778607.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 67190809 + 3496900 = 8197^2 + 1870^2 .

It is an emirp because it is prime and its reverse (90778607) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 70687709 - 2⁸ = 70687453 is a prime.

It is a Sophie Germain prime.

Together with 70687711, it forms a pair of twin primes.

It is a Chen prime.

It is a Curzon number.

It is a self number, because there is not a number n which added to its sum of digits gives 70687709.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (70687739) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 35343854 + 35343855.

It is an arithmetic number, because the mean of its divisors is an integer number (35343855).

Almost surely, 2^70687709 is an apocalyptic number.

It is an amenable number.

70687709 is a deficient number, since it is larger than the sum of its proper divisors (1).

70687709 is an equidigital number, since it uses as much as digits as its factorization.

70687709 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 148176, while the sum is 44.

The square root of 70687709 is about 8407.5982896425. The cubic root of 70687709 is about 413.4737746108.

The spelling of 70687709 in words is "seventy million, six hundred eighty-seven thousand, seven hundred nine".