2561376857531 has 8 divisors (see below), whose sum is σ = 2673200363424. Its totient is φ = 2449591626240.

The previous prime is 2561376857527. The next prime is 2561376857563. The reversal of 2561376857531 is 1357586731652.

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

It is a cyclic number.

It is not a de Polignac number, because 2561376857531 - 2² = 2561376857527 is a prime.

It is a super-2 number, since 2×2561376857531² (a number of 26 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (2561376857591) 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, 9431846 + ... + 9699611.

It is an arithmetic number, because the mean of its divisors is an integer number (334150045428).

Almost surely, 2^{2561376857531} is an apocalyptic number.

2561376857531 is a deficient number, since it is larger than the sum of its proper divisors (111823505893).

2561376857531 is a wasteful number, since it uses less digits than its factorization.

2561376857531 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 19137301.

The product of its digits is 31752000, while the sum is 59.

The spelling of 2561376857531 in words is "two trillion, five hundred sixty-one billion, three hundred seventy-six million, eight hundred fifty-seven thousand, five hundred thirty-one".