1656561 has 8 divisors (see below), whose sum is σ = 2220064. Its totient is φ = 1098720.

The previous prime is 1656559. The next prime is 1656563.

1656561 is nontrivially palindromic in base 10.

It is an interprime number because it is at equal distance from previous prime (1656559) and next prime (1656563).

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

It is not a de Polignac number, because 1656561 - 2¹ = 1656559 is a prime.

It is an alternating number because its digits alternate between odd and even.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1656563) 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, 676 + ... + 1941.

It is an arithmetic number, because the mean of its divisors is an integer number (277508).

2^1656561 is an apocalyptic number.

It is an amenable number.

1656561 is a deficient number, since it is larger than the sum of its proper divisors (563503).

1656561 is a wasteful number, since it uses less digits than its factorization.

1656561 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2831.

The product of its digits is 5400, while the sum is 30.

The square root of 1656561 is about 1287.0745899131. The cubic root of 1656561 is about 118.3229923296.

The spelling of 1656561 in words is "one million, six hundred fifty-six thousand, five hundred sixty-one".