2561878225 has 27 divisors (see below), whose sum is σ = 3254838769. Its totient is φ = 2000304800.

The previous prime is 2561878219. The next prime is 2561878229. The reversal of 2561878225 is 5228781652.

The square root of 2561878225 is 50615.

It is a perfect power (a square), and thus also a powerful number.

It can be written as a sum of positive squares in 4 ways, for example, as 19298449 + 2542579776 = 4393^2 + 50424^2 .

It is not a de Polignac number, because 2561878225 - 2¹³ = 2561870033 is a prime.

It is a Duffinian number.

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 26 ways as a sum of consecutive naturals, for example, 13412880 + ... + 13413070.

Almost surely, 2^2561878225 is an apocalyptic number.

2561878225 is a gapful number since it is divisible by the number (25) formed by its first and last digit.

2561878225 is the 50615-th square number.

2561878225 is the 25308-th centered octagonal number.

It is an amenable number.

2561878225 is a deficient number, since it is larger than the sum of its proper divisors (692960544).

2561878225 is an frugal number, since it uses more digits than its factorization.

2561878225 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 498 (or 249 counting only the distinct ones).

The product of its digits is 537600, while the sum is 46.

The cubic root of 2561878225 is about 1368.3152296781.

The spelling of 2561878225 in words is "two billion, five hundred sixty-one million, eight hundred seventy-eight thousand, two hundred twenty-five".