13070821 has 2 divisors, whose sum is σ = 13070822. Its totient is φ = 13070820.

The previous prime is 13070819. The next prime is 13070833. The reversal of 13070821 is 12807031.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 6890625 + 6180196 = 2625^2 + 2486^2 .

It is a cyclic number.

It is not a de Polignac number, because 13070821 - 2¹ = 13070819 is a prime.

It is a super-2 number, since 2×13070821² = 341692723228082, which contains 22 as substring.

Together with 13070819, it forms a pair of twin primes.

It is a junction number, because it is equal to n+sod(n) for n = 13070792 and 13070801.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (13070891) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 6535410 + 6535411.

It is an arithmetic number, because the mean of its divisors is an integer number (6535411).

Almost surely, 2^13070821 is an apocalyptic number.

It is an amenable number.

13070821 is a deficient number, since it is larger than the sum of its proper divisors (1).

13070821 is an equidigital number, since it uses as much as digits as its factorization.

13070821 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 336, while the sum is 22.

The square root of 13070821 is about 3615.3590416444. The cubic root of 13070821 is about 235.5596800317.

Adding to 13070821 its reverse (12807031), we get a palindrome (25877852).

The spelling of 13070821 in words is "thirteen million, seventy thousand, eight hundred twenty-one".