2561131281 has 8 divisors (see below), whose sum is σ = 3415164064. Its totient is φ = 1707259680.

The previous prime is 2561131219. The next prime is 2561131303. The reversal of 2561131281 is 1821311652.

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

It is not a de Polignac number, because 2561131281 - 2⁶ = 2561131217 is a prime.

It is a super-2 number, since 2×2561131281² = 13118786877033401922, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (2561131211) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 3621 + ... + 71661.

It is an arithmetic number, because the mean of its divisors is an integer number (426895508).

Almost surely, 2^2561131281 is an apocalyptic number.

It is an amenable number.

2561131281 is a deficient number, since it is larger than the sum of its proper divisors (854032783).

2561131281 is a wasteful number, since it uses less digits than its factorization.

2561131281 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 80591.

The product of its digits is 2880, while the sum is 30.

The square root of 2561131281 is about 50607.6207798786. The cubic root of 2561131281 is about 1368.1822342599.

The spelling of 2561131281 in words is "two billion, five hundred sixty-one million, one hundred thirty-one thousand, two hundred eighty-one".