1661404 has 12 divisors (see below), whose sum is σ = 2918944. Its totient is φ = 827424.

The previous prime is 1661353. The next prime is 1661431. The reversal of 1661404 is 4041661.

It is a hoax number, since the sum of its digits (22) coincides with the sum of the digits of its distinct prime factors.

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, 589 + ... + 1915.

2^1661404 is an apocalyptic number.

It is an amenable number.

1661404 is a deficient number, since it is larger than the sum of its proper divisors (1257540).

1661404 is a wasteful number, since it uses less digits than its factorization.

1661404 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1644 (or 1642 counting only the distinct ones).

The product of its (nonzero) digits is 576, while the sum is 22.

The square root of 1661404 is about 1288.9546151824. The cubic root of 1661404 is about 118.4381869459.

The spelling of 1661404 in words is "one million, six hundred sixty-one thousand, four hundred four".