2561295009 has 32 divisors (see below), whose sum is σ = 4260761344. Its totient is φ = 1332495360.

The previous prime is 2561294941. The next prime is 2561295031. The reversal of 2561295009 is 9005921652.

It is not a de Polignac number, because 2561295009 - 2⁹ = 2561294497 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (39).

It is not an unprimeable number, because it can be changed into a prime (2561295509) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 44332 + ... + 84189.

It is an arithmetic number, because the mean of its divisors is an integer number (133148792).

Almost surely, 2^2561295009 is an apocalyptic number.

It is an amenable number.

2561295009 is a deficient number, since it is larger than the sum of its proper divisors (1699466335).

2561295009 is a wasteful number, since it uses less digits than its factorization.

2561295009 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 128617.

The product of its (nonzero) digits is 48600, while the sum is 39.

The square root of 2561295009 is about 50609.2383760119. The cubic root of 2561295009 is about 1368.2113886899.

The spelling of 2561295009 in words is "two billion, five hundred sixty-one million, two hundred ninety-five thousand, nine".