408990 has 16 divisors (see below), whose sum is σ = 981648. Its totient is φ = 109056.

The previous prime is 408979. The next prime is 408997. The reversal of 408990 is 99804.

408990 = 284² + 285² + ... + 288².

It is a Harshad number since it is a multiple of its sum of digits (30), and also a Moran number because the ratio is a prime number: 13633 = 408990 / (4 + 0 + 8 + 9 + 9 + 0).

It is a congruent number.

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 408990.

It is not an unprimeable number, because it can be changed into a prime (408997) by changing a digit.

408990 is an untouchable number, because it is not equal to the sum of proper divisors of any number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 6787 + ... + 6846.

It is an arithmetic number, because the mean of its divisors is an integer number (61353).

2⁴⁰⁸⁹⁹⁰ is an apocalyptic number.

408990 is an abundant number, since it is smaller than the sum of its proper divisors (572658).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

408990 is a wasteful number, since it uses less digits than its factorization.

408990 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 13643.

The product of its (nonzero) digits is 2592, while the sum is 30.

The square root of 408990 is about 639.5232599366. The cubic root of 408990 is about 74.2285362350.

The spelling of 408990 in words is "four hundred eight thousand, nine hundred ninety".