1604661 has 8 divisors (see below), whose sum is σ = 2148384. Its totient is φ = 1065360.

The previous prime is 1604651. The next prime is 1604711. The reversal of 1604661 is 1664061.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 1604661 - 2⁶ = 1604597 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1604611) 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 7 ways as a sum of consecutive naturals, for example, 135 + ... + 1796.

It is an arithmetic number, because the mean of its divisors is an integer number (268548).

2^1604661 is an apocalyptic number.

It is an amenable number.

1604661 is a deficient number, since it is larger than the sum of its proper divisors (543723).

1604661 is a wasteful number, since it uses less digits than its factorization.

1604661 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2211.

The product of its (nonzero) digits is 864, while the sum is 24.

The square root of 1604661 is about 1266.7521462386. The cubic root of 1604661 is about 117.0741731442.

The spelling of 1604661 in words is "one million, six hundred four thousand, six hundred sixty-one".