404981 has 2 divisors, whose sum is σ = 404982. Its totient is φ = 404980.

The previous prime is 404977. The next prime is 404983. The reversal of 404981 is 189404.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 401956 + 3025 = 634^2 + 55^2 .

It is a cyclic number.

It is not a de Polignac number, because 404981 - 2² = 404977 is a prime.

It is a super-2 number, since 2×404981² = 328019220722, which contains 22 as substring.

Together with 404983, it forms a pair of twin primes.

It is a Chen prime.

It is a plaindrome in base 13.

It is a self number, because there is not a number n which added to its sum of digits gives 404981.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (404983) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 202490 + 202491.

It is an arithmetic number, because the mean of its divisors is an integer number (202491).

2⁴⁰⁴⁹⁸¹ is an apocalyptic number.

It is an amenable number.

404981 is a deficient number, since it is larger than the sum of its proper divisors (1).

404981 is an equidigital number, since it uses as much as digits as its factorization.

404981 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 1152, while the sum is 26.

The square root of 404981 is about 636.3811750830. The cubic root of 404981 is about 73.9852052234.

The spelling of 404981 in words is "four hundred four thousand, nine hundred eighty-one".