408621 has 4 divisors (see below), whose sum is σ = 544832. Its totient is φ = 272412.

The previous prime is 408607. The next prime is 408623. The reversal of 408621 is 126804.

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 408621 - 2¹¹ = 406573 is a prime.

It is a super-2 number, since 2×408621² = 333942243282, 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 (408623) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 68101 + ... + 68106.

It is an arithmetic number, because the mean of its divisors is an integer number (136208).

2⁴⁰⁸⁶²¹ is an apocalyptic number.

It is an amenable number.

408621 is a deficient number, since it is larger than the sum of its proper divisors (136211).

408621 is a wasteful number, since it uses less digits than its factorization.

408621 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 136210.

The product of its (nonzero) digits is 384, while the sum is 21.

The square root of 408621 is about 639.2346986827. The cubic root of 408621 is about 74.2062059649.

The spelling of 408621 in words is "four hundred eight thousand, six hundred twenty-one".