2561261043 has 8 divisors (see below), whose sum is σ = 3725470656. Its totient is φ = 1552279400.

The previous prime is 2561261039. The next prime is 2561261069. The reversal of 2561261043 is 3401621652.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 2561261043 - 2² = 2561261039 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 2561261043.

It is not an unprimeable number, because it can be changed into a prime (2561260043) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 38806953 + ... + 38807018.

It is an arithmetic number, because the mean of its divisors is an integer number (465683832).

Almost surely, 2^2561261043 is an apocalyptic number.

2561261043 is a deficient number, since it is larger than the sum of its proper divisors (1164209613).

2561261043 is a wasteful number, since it uses less digits than its factorization.

2561261043 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 77613985.

The product of its (nonzero) digits is 8640, while the sum is 30.

The square root of 2561261043 is about 50608.9028037558. The cubic root of 2561261043 is about 1368.2053405940.

Adding to 2561261043 its reverse (3401621652), we get a palindrome (5962882695).

The spelling of 2561261043 in words is "two billion, five hundred sixty-one million, two hundred sixty-one thousand, forty-three".