3402821 has 2 divisors, whose sum is σ = 3402822. Its totient is φ = 3402820.

The previous prime is 3402803. The next prime is 3402823. The reversal of 3402821 is 1282043.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 3290596 + 112225 = 1814^2 + 335^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-3402821 is a prime.

It is a super-4 number, since 4×3402821⁴ (a number of 27 digits) contains 4444 as substring.

Together with 3402823, it forms a pair of twin primes.

It is a Chen prime.

It is a junction number, because it is equal to n+sod(n) for n = 3402793 and 3402802.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (3402823) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1701410 + 1701411.

It is an arithmetic number, because the mean of its divisors is an integer number (1701411).

Almost surely, 2^3402821 is an apocalyptic number.

It is an amenable number.

3402821 is a deficient number, since it is larger than the sum of its proper divisors (1).

3402821 is an equidigital number, since it uses as much as digits as its factorization.

3402821 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 384, while the sum is 20.

The square root of 3402821 is about 1844.6736838802. The cubic root of 3402821 is about 150.4110355991.

Adding to 3402821 its reverse (1282043), we get a palindrome (4684864).

The spelling of 3402821 in words is "three million, four hundred two thousand, eight hundred twenty-one".