1606561 has 4 divisors (see below), whose sum is σ = 1752624. Its totient is φ = 1460500.

The previous prime is 1606559. The next prime is 1606597. The reversal of 1606561 is 1656061.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also an emirpimes, since its reverse is a distinct semiprime: 1656061 = 11 ⋅150551.

It is a cyclic number.

It is not a de Polignac number, because 1606561 - 2¹ = 1606559 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1606541) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 73015 + ... + 73036.

It is an arithmetic number, because the mean of its divisors is an integer number (438156).

2^1606561 is an apocalyptic number.

1606561 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

It is an amenable number.

1606561 is a deficient number, since it is larger than the sum of its proper divisors (146063).

1606561 is a wasteful number, since it uses less digits than its factorization.

1606561 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 146062.

The product of its (nonzero) digits is 1080, while the sum is 25.

The square root of 1606561 is about 1267.5018737659. The cubic root of 1606561 is about 117.1203621716.

The spelling of 1606561 in words is "one million, six hundred six thousand, five hundred sixty-one".