69842821 has 2 divisors, whose sum is σ = 69842822. Its totient is φ = 69842820.

The previous prime is 69842819. The next prime is 69842827. The reversal of 69842821 is 12824896.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 44742721 + 25100100 = 6689^2 + 5010^2 .

It is a cyclic number.

It is not a de Polignac number, because 69842821 - 2¹ = 69842819 is a prime.

Together with 69842819, 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 (69842827) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 34921410 + 34921411.

It is an arithmetic number, because the mean of its divisors is an integer number (34921411).

Almost surely, 2^69842821 is an apocalyptic number.

It is an amenable number.

69842821 is a deficient number, since it is larger than the sum of its proper divisors (1).

69842821 is an equidigital number, since it uses as much as digits as its factorization.

69842821 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 55296, while the sum is 40.

The square root of 69842821 is about 8357.2017446033. The cubic root of 69842821 is about 411.8198323845.

The spelling of 69842821 in words is "sixty-nine million, eight hundred forty-two thousand, eight hundred twenty-one".