6131561 has 2 divisors, whose sum is σ = 6131562. Its totient is φ = 6131560.

The previous prime is 6131551. The next prime is 6131597. The reversal of 6131561 is 1651316.

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., 5669161 + 462400 = 2381^2 + 680^2 .

It is a cyclic number.

It is not a de Polignac number, because 6131561 - 2¹⁸ = 5869417 is a prime.

It is a Sophie Germain prime.

It is a Chen prime.

It is a Curzon number.

It is not a weakly prime, because it can be changed into another prime (6131551) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 3065780 + 3065781.

It is an arithmetic number, because the mean of its divisors is an integer number (3065781).

Almost surely, 2^6131561 is an apocalyptic number.

It is an amenable number.

6131561 is a deficient number, since it is larger than the sum of its proper divisors (1).

6131561 is an equidigital number, since it uses as much as digits as its factorization.

6131561 is an evil number, because the sum of its binary digits is even.

The product of its digits is 540, while the sum is 23.

The square root of 6131561 is about 2476.1989015424. The cubic root of 6131561 is about 183.0305919972.

Adding to 6131561 its reverse (1651316), we get a palindrome (7782877).

The spelling of 6131561 in words is "six million, one hundred thirty-one thousand, five hundred sixty-one".