2561154122556 has 72 divisors (see below), whose sum is σ = 6573974687280. Its totient is φ = 840627680256.

The previous prime is 2561154122539. The next prime is 2561154122591. The reversal of 2561154122556 is 6552214511652.

It is a happy number.

2561154122556 is a `hidden beast` number, since 2 + 5 + 61 + 15 + 4 + 1 + 22 + 556 = 666.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 1173586 + ... + 2549433.

It is an arithmetic number, because the mean of its divisors is an integer number (91305203990).

Almost surely, 2^{2561154122556} is an apocalyptic number.

It is an amenable number.

2561154122556 is an abundant number, since it is smaller than the sum of its proper divisors (4012820564724).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

2561154122556 is a wasteful number, since it uses less digits than its factorization.

2561154122556 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3723323 (or 3723318 counting only the distinct ones).

The product of its digits is 720000, while the sum is 45.

The spelling of 2561154122556 in words is "two trillion, five hundred sixty-one billion, one hundred fifty-four million, one hundred twenty-two thousand, five hundred fifty-six".