2861561 has 2 divisors, whose sum is σ = 2861562. Its totient is φ = 2861560.

The previous prime is 2861557. The next prime is 2861569. The reversal of 2861561 is 1651682.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 1525225 + 1336336 = 1235^2 + 1156^2 .

It is a cyclic number.

It is not a de Polignac number, because 2861561 - 2² = 2861557 is a prime.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (2861569) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1430780 + 1430781.

It is an arithmetic number, because the mean of its divisors is an integer number (1430781).

2^2861561 is an apocalyptic number.

It is an amenable number.

2861561 is a deficient number, since it is larger than the sum of its proper divisors (1).

2861561 is an equidigital number, since it uses as much as digits as its factorization.

2861561 is an evil number, because the sum of its binary digits is even.

The product of its digits is 2880, while the sum is 29.

The square root of 2861561 is about 1691.6149088962. The cubic root of 2861561 is about 141.9714450286.

The spelling of 2861561 in words is "two million, eight hundred sixty-one thousand, five hundred sixty-one".