70565821 has 2 divisors, whose sum is σ = 70565822. Its totient is φ = 70565820.

The previous prime is 70565819. The next prime is 70565839. The reversal of 70565821 is 12856507.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 62647225 + 7918596 = 7915^2 + 2814^2 .

It is an emirp because it is prime and its reverse (12856507) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 70565821 - 2¹ = 70565819 is a prime.

Together with 70565819, it forms a pair of twin primes.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (70568821) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 35282910 + 35282911.

It is an arithmetic number, because the mean of its divisors is an integer number (35282911).

Almost surely, 2^70565821 is an apocalyptic number.

It is an amenable number.

70565821 is a deficient number, since it is larger than the sum of its proper divisors (1).

70565821 is an equidigital number, since it uses as much as digits as its factorization.

70565821 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 16800, while the sum is 34.

The square root of 70565821 is about 8400.3464809495. The cubic root of 70565821 is about 413.2359846328.

The spelling of 70565821 in words is "seventy million, five hundred sixty-five thousand, eight hundred twenty-one".