2561971 has 4 divisors (see below), whose sum is σ = 2582272. Its totient is φ = 2541672.

The previous prime is 2561969. The next prime is 2561981. The reversal of 2561971 is 1791652.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 2561971 - 2¹ = 2561969 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (2561921) 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 3 ways as a sum of consecutive naturals, for example, 9960 + ... + 10213.

It is an arithmetic number, because the mean of its divisors is an integer number (645568).

2^2561971 is an apocalyptic number.

2561971 is a deficient number, since it is larger than the sum of its proper divisors (20301).

2561971 is a wasteful number, since it uses less digits than its factorization.

2561971 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 20300.

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

The square root of 2561971 is about 1600.6158189897. The cubic root of 2561971 is about 136.8331746715.

The spelling of 2561971 in words is "two million, five hundred sixty-one thousand, nine hundred seventy-one".