2561979 has 16 divisors (see below), whose sum is σ = 4110080. Its totient is φ = 1386720.

The previous prime is 2561969. The next prime is 2561981. The reversal of 2561979 is 9791652.

It is not a de Polignac number, because 2561979 - 2⁴ = 2561963 is a prime.

It is not an unprimeable number, because it can be changed into a prime (2561929) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 2812 + ... + 3609.

It is an arithmetic number, because the mean of its divisors is an integer number (256880).

2^2561979 is an apocalyptic number.

2561979 is a deficient number, since it is larger than the sum of its proper divisors (1548101).

2561979 is a wasteful number, since it uses less digits than its factorization.

2561979 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6450.

The product of its digits is 34020, while the sum is 39.

The square root of 2561979 is about 1600.6183180259. The cubic root of 2561979 is about 136.8333170963.

The spelling of 2561979 in words is "two million, five hundred sixty-one thousand, nine hundred seventy-nine".