13670821 has 2 divisors, whose sum is σ = 13670822. Its totient is φ = 13670820.

The previous prime is 13670801. The next prime is 13670827. The reversal of 13670821 is 12807631.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 10797796 + 2873025 = 3286^2 + 1695^2 .

It is a cyclic number.

It is not a de Polignac number, because 13670821 - 2¹³ = 13662629 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 13670821.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (13670827) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 6835410 + 6835411.

It is an arithmetic number, because the mean of its divisors is an integer number (6835411).

Almost surely, 2^13670821 is an apocalyptic number.

It is an amenable number.

13670821 is a deficient number, since it is larger than the sum of its proper divisors (1).

13670821 is an equidigital number, since it uses as much as digits as its factorization.

13670821 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 2016, while the sum is 28.

The square root of 13670821 is about 3697.4073348767. The cubic root of 13670821 is about 239.1102529893.

The spelling of 13670821 in words is "thirteen million, six hundred seventy thousand, eight hundred twenty-one".