2561131545 has 32 divisors (see below), whose sum is σ = 4689592320. Its totient is φ = 1169208000.

The previous prime is 2561131541. The next prime is 2561131597. The reversal of 2561131545 is 5451311652.

It is not a de Polignac number, because 2561131545 - 2² = 2561131541 is a prime.

It is not an unprimeable number, because it can be changed into a prime (2561131541) 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, 62616 + ... + 95094.

It is an arithmetic number, because the mean of its divisors is an integer number (146549760).

Almost surely, 2^2561131545 is an apocalyptic number.

It is an amenable number.

2561131545 is a deficient number, since it is larger than the sum of its proper divisors (2128460775).

2561131545 is a wasteful number, since it uses less digits than its factorization.

2561131545 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 33245.

The product of its digits is 18000, while the sum is 33.

The square root of 2561131545 is about 50607.6233881814. The cubic root of 2561131545 is about 1368.1822812704.

The spelling of 2561131545 in words is "two billion, five hundred sixty-one million, one hundred thirty-one thousand, five hundred forty-five".