408981 has 4 divisors (see below), whose sum is σ = 545312. Its totient is φ = 272652.

The previous prime is 408979. The next prime is 408997. The reversal of 408981 is 189804.

It is a happy number.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is not a de Polignac number, because 408981 - 2¹ = 408979 is a prime.

It is a super-2 number, since 2×408981² = 334530916722, which contains 22 as substring.

It is a D-number.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (408911) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 68161 + ... + 68166.

It is an arithmetic number, because the mean of its divisors is an integer number (136328).

2⁴⁰⁸⁹⁸¹ is an apocalyptic number.

It is an amenable number.

408981 is a deficient number, since it is larger than the sum of its proper divisors (136331).

408981 is a wasteful number, since it uses less digits than its factorization.

408981 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 136330.

The product of its (nonzero) digits is 2304, while the sum is 30.

The square root of 408981 is about 639.5162234064. The cubic root of 408981 is about 74.2279917541.

The spelling of 408981 in words is "four hundred eight thousand, nine hundred eighty-one".