403980821 has 2 divisors, whose sum is σ = 403980822. Its totient is φ = 403980820.

The previous prime is 403980803. The next prime is 403980827. The reversal of 403980821 is 128089304.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 229371025 + 174609796 = 15145^2 + 13214^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-403980821 is a prime.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (403980827) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 201990410 + 201990411.

It is an arithmetic number, because the mean of its divisors is an integer number (201990411).

Almost surely, 2^403980821 is an apocalyptic number.

It is an amenable number.

403980821 is a deficient number, since it is larger than the sum of its proper divisors (1).

403980821 is an equidigital number, since it uses as much as digits as its factorization.

403980821 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 13824, while the sum is 35.

The square root of 403980821 is about 20099.2741411226. The cubic root of 403980821 is about 739.2424808378.

The spelling of 403980821 in words is "four hundred three million, nine hundred eighty thousand, eight hundred twenty-one".