2561878226 has 8 divisors (see below), whose sum is σ = 3862324620. Its totient is φ = 1274436688.

The previous prime is 2561878219. The next prime is 2561878229. The reversal of 2561878226 is 6228781652.

It is a Cunningham number, because it is equal to 50615²+1.

It can be written as a sum of positive squares in 2 ways, for example, as 2561878225 + 1 = 50615^2 + 1^2 .

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

It is not an unprimeable number, because it can be changed into a prime (2561878229) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 3250721 + ... + 3251508.

Almost surely, 2^2561878226 is an apocalyptic number.

2561878226 is a deficient number, since it is larger than the sum of its proper divisors (1300446394).

2561878226 is a wasteful number, since it uses less digits than its factorization.

2561878226 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6502428.

The product of its digits is 645120, while the sum is 47.

The square root of 2561878226 is about 50615.0000098785. Note that the first 5 decimals coincide. The cubic root of 2561878226 is about 1368.3152298561.

The spelling of 2561878226 in words is "two billion, five hundred sixty-one million, eight hundred seventy-eight thousand, two hundred twenty-six".