2561111431 has 4 divisors (see below), whose sum is σ = 2567026672. Its totient is φ = 2555196192.

The previous prime is 2561111429. The next prime is 2561111461. The reversal of 2561111431 is 1341111652.

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 2561111431 - 2¹ = 2561111429 is a prime.

It is a super-2 number, since 2×2561111431² = 13118583523997735522, which contains 22 as substring.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 2561111396 and 2561111405.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2561111411) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2956971 + ... + 2957836.

It is an arithmetic number, because the mean of its divisors is an integer number (641756668).

Almost surely, 2^2561111431 is an apocalyptic number.

2561111431 is a deficient number, since it is larger than the sum of its proper divisors (5915241).

2561111431 is an equidigital number, since it uses as much as digits as its factorization.

2561111431 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5915240.

The product of its digits is 720, while the sum is 25.

The square root of 2561111431 is about 50607.4246627903. The cubic root of 2561111431 is about 1368.1786995605.

The spelling of 2561111431 in words is "two billion, five hundred sixty-one million, one hundred eleven thousand, four hundred thirty-one".