1601561 has 8 divisors (see below), whose sum is σ = 1734600. Its totient is φ = 1469952.

The previous prime is 1601543. The next prime is 1601563. The reversal of 1601561 is 1651061.

It is a happy number.

It can be written as a sum of positive squares in 4 ways, for example, as 115600 + 1485961 = 340^2 + 1219^2 .

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

It is a cyclic number.

It is not a de Polignac number, because 1601561 - 2¹⁰ = 1600537 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1601563) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 4361 + ... + 4713.

It is an arithmetic number, because the mean of its divisors is an integer number (216825).

2^1601561 is an apocalyptic number.

It is an amenable number.

1601561 is a deficient number, since it is larger than the sum of its proper divisors (133039).

1601561 is a wasteful number, since it uses less digits than its factorization.

1601561 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 715.

The product of its (nonzero) digits is 180, while the sum is 20.

The square root of 1601561 is about 1265.5279530694. The cubic root of 1601561 is about 116.9987337628.

The spelling of 1601561 in words is "one million, six hundred one thousand, five hundred sixty-one".