1606661 has 6 divisors (see below), whose sum is σ = 1869030. Its totient is φ = 1377096.

The previous prime is 1606643. The next prime is 1606663. The reversal of 1606661 is 1666061.

It can be written as a sum of positive squares in only one way, i.e., 1366561 + 240100 = 1169^2 + 490^2 .

It is not a de Polignac number, because 1606661 - 2⁶ = 1606597 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 1606661.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1606663) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 16346 + ... + 16443.

It is an arithmetic number, because the mean of its divisors is an integer number (311505).

2^1606661 is an apocalyptic number.

It is an amenable number.

1606661 is a deficient number, since it is larger than the sum of its proper divisors (262369).

1606661 is an equidigital number, since it uses as much as digits as its factorization.

1606661 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 32803 (or 32796 counting only the distinct ones).

The product of its (nonzero) digits is 1296, while the sum is 26.

The square root of 1606661 is about 1267.5413208255. The cubic root of 1606661 is about 117.1227921640.

The spelling of 1606661 in words is "one million, six hundred six thousand, six hundred sixty-one".