3501821 has 2 divisors, whose sum is σ = 3501822. Its totient is φ = 3501820.

The previous prime is 3501811. The next prime is 3501863. The reversal of 3501821 is 1281053.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 2839225 + 662596 = 1685^2 + 814^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-3501821 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 3501793 and 3501802.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (3501811) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1750910 + 1750911.

It is an arithmetic number, because the mean of its divisors is an integer number (1750911).

Almost surely, 2^3501821 is an apocalyptic number.

It is an amenable number.

3501821 is a deficient number, since it is larger than the sum of its proper divisors (1).

3501821 is an equidigital number, since it uses as much as digits as its factorization.

3501821 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 240, while the sum is 20.

The square root of 3501821 is about 1871.3153128214. The cubic root of 3501821 is about 151.8557755928.

Adding to 3501821 its reverse (1281053), we get a palindrome (4782874).

The spelling of 3501821 in words is "three million, five hundred one thousand, eight hundred twenty-one".