2791561 has 2 divisors, whose sum is σ = 2791562. Its totient is φ = 2791560.

The previous prime is 2791559. The next prime is 2791577. The reversal of 2791561 is 1651972.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 2673225 + 118336 = 1635^2 + 344^2 .

It is a cyclic number.

It is not a de Polignac number, because 2791561 - 2¹ = 2791559 is a prime.

Together with 2791559, it forms a pair of twin primes.

It is not a weakly prime, because it can be changed into another prime (2791501) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1395780 + 1395781.

It is an arithmetic number, because the mean of its divisors is an integer number (1395781).

2^2791561 is an apocalyptic number.

It is an amenable number.

2791561 is a deficient number, since it is larger than the sum of its proper divisors (1).

2791561 is an equidigital number, since it uses as much as digits as its factorization.

2791561 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 3780, while the sum is 31.

The square root of 2791561 is about 1670.7965166351. The cubic root of 2791561 is about 140.8042317782.

The spelling of 2791561 in words is "two million, seven hundred ninety-one thousand, five hundred sixty-one".