1661408 has 24 divisors (see below), whose sum is σ = 3738672. Its totient is φ = 711936.

The previous prime is 1661353. The next prime is 1661431. The reversal of 1661408 is 8041661.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 3485 + ... + 3932.

It is an arithmetic number, because the mean of its divisors is an integer number (155778).

2^1661408 is an apocalyptic number.

It is an amenable number.

1661408 is an abundant number, since it is smaller than the sum of its proper divisors (2077264).

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

1661408 is an equidigital number, since it uses as much as digits as its factorization.

1661408 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7434 (or 7426 counting only the distinct ones).

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

The square root of 1661408 is about 1288.9561668265. The cubic root of 1661408 is about 118.4382819965.

The spelling of 1661408 in words is "one million, six hundred sixty-one thousand, four hundred eight".