2561965 has 12 divisors (see below), whose sum is σ = 3576636. Its totient is φ = 1756608.

The previous prime is 2561963. The next prime is 2561969. The reversal of 2561965 is 5691652.

It is a happy number.

It can be written as a sum of positive squares in 2 ways, for example, as 1695204 + 866761 = 1302^2 + 931^2 .

It is not a de Polignac number, because 2561965 - 2¹ = 2561963 is a prime.

It is a super-2 number, since 2×2561965² = 13127329322450, which contains 22 as substring.

2561965 is a lucky number.

It is a self number, because there is not a number n which added to its sum of digits gives 2561965.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2561963) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 4984 + ... + 5473.

It is an arithmetic number, because the mean of its divisors is an integer number (298053).

2^2561965 is an apocalyptic number.

It is an amenable number.

2561965 is a deficient number, since it is larger than the sum of its proper divisors (1014671).

2561965 is a wasteful number, since it uses less digits than its factorization.

2561965 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10476 (or 10469 counting only the distinct ones).

The product of its digits is 16200, while the sum is 34.

The square root of 2561965 is about 1600.6139447100. The cubic root of 2561965 is about 136.8330678528.

The spelling of 2561965 in words is "two million, five hundred sixty-one thousand, nine hundred sixty-five".