2540555355521 has 4 divisors (see below), whose sum is σ = 2565709369044. Its totient is φ = 2515401342000.

The previous prime is 2540555355487. The next prime is 2540555355539. The reversal of 2540555355521 is 1255535550452.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 1490135345521 + 1050420010000 = 1220711^2 + 1024900^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-2540555355521 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (2540555355721) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 12577006610 + ... + 12577006811.

It is an arithmetic number, because the mean of its divisors is an integer number (641427342261).

Almost surely, 2^{2540555355521} is an apocalyptic number.

It is an amenable number.

2540555355521 is a deficient number, since it is larger than the sum of its proper divisors (25154013523).

2540555355521 is a wasteful number, since it uses less digits than its factorization.

2540555355521 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 25154013522.

The product of its (nonzero) digits is 3750000, while the sum is 47.

The spelling of 2540555355521 in words is "two trillion, five hundred forty billion, five hundred fifty-five million, three hundred fifty-five thousand, five hundred twenty-one".