3101561 has 4 divisors (see below), whose sum is σ = 3136500. Its totient is φ = 3066624.

The previous prime is 3101557. The next prime is 3101591. The reversal of 3101561 is 1651013.

3101561 is nontrivially palindromic in base 11.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 295936 + 2805625 = 544^2 + 1675^2 .

It is a cyclic number.

It is not a de Polignac number, because 3101561 - 2² = 3101557 is a prime.

It is an Ulam number.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (3101591) 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, 17336 + ... + 17513.

It is an arithmetic number, because the mean of its divisors is an integer number (784125).

Almost surely, 2^3101561 is an apocalyptic number.

It is an amenable number.

3101561 is a deficient number, since it is larger than the sum of its proper divisors (34939).

3101561 is an equidigital number, since it uses as much as digits as its factorization.

3101561 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 34938.

The product of its (nonzero) digits is 90, while the sum is 17.

The square root of 3101561 is about 1761.1249245866. The cubic root of 3101561 is about 145.8344436015.

Adding to 3101561 its reverse (1651013), we get a palindrome (4752574).

The spelling of 3101561 in words is "three million, one hundred one thousand, five hundred sixty-one".