7961561 has 2 divisors, whose sum is σ = 7961562. Its totient is φ = 7961560.

The previous prime is 7961557. The next prime is 7961563. The reversal of 7961561 is 1651697.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 7595536 + 366025 = 2756^2 + 605^2 .

It is a cyclic number.

It is not a de Polignac number, because 7961561 - 2² = 7961557 is a prime.

It is a Sophie Germain prime.

Together with 7961563, it forms a pair of twin primes.

It is a Chen prime.

It is a Curzon number.

It is not a weakly prime, because it can be changed into another prime (7961563) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 3980780 + 3980781.

It is an arithmetic number, because the mean of its divisors is an integer number (3980781).

Almost surely, 2^7961561 is an apocalyptic number.

It is an amenable number.

7961561 is a deficient number, since it is larger than the sum of its proper divisors (1).

7961561 is an equidigital number, since it uses as much as digits as its factorization.

7961561 is an evil number, because the sum of its binary digits is even.

The product of its digits is 11340, while the sum is 35.

The square root of 7961561 is about 2821.6238232621. The cubic root of 7961561 is about 199.6791605856.

The spelling of 7961561 in words is "seven million, nine hundred sixty-one thousand, five hundred sixty-one".