2642561 has 2 divisors, whose sum is σ = 2642562. Its totient is φ = 2642560.

The previous prime is 2642543. The next prime is 2642569. The reversal of 2642561 is 1652462.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 2640625 + 1936 = 1625^2 + 44^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-2642561 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 2642561.

It is not a weakly prime, because it can be changed into another prime (2642569) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1321280 + 1321281.

It is an arithmetic number, because the mean of its divisors is an integer number (1321281).

2^2642561 is an apocalyptic number.

It is an amenable number.

2642561 is a deficient number, since it is larger than the sum of its proper divisors (1).

2642561 is an equidigital number, since it uses as much as digits as its factorization.

2642561 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 2880, while the sum is 26.

The square root of 2642561 is about 1625.5955831633. The cubic root of 2642561 is about 138.2531410505.

Subtracting from 2642561 its reverse (1652462), we obtain a palindrome (990099).

The spelling of 2642561 in words is "two million, six hundred forty-two thousand, five hundred sixty-one".