11525451521 has 4 divisors (see below), whose sum is σ = 11525765700. Its totient is φ = 11525137344.

The previous prime is 11525451517. The next prime is 11525451559. The reversal of 11525451521 is 12515452511.

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 10044048400 + 1481403121 = 100220^2 + 38489^2 .

It is a cyclic number.

It is not a de Polignac number, because 11525451521 - 2² = 11525451517 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (11525451221) 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, 93476 + ... + 178293.

It is an arithmetic number, because the mean of its divisors is an integer number (2881441425).

Almost surely, 2^11525451521 is an apocalyptic number.

It is an amenable number.

11525451521 is a deficient number, since it is larger than the sum of its proper divisors (314179).

11525451521 is an equidigital number, since it uses as much as digits as its factorization.

11525451521 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 314178.

The product of its digits is 10000, while the sum is 32.

The spelling of 11525451521 in words is "eleven billion, five hundred twenty-five million, four hundred fifty-one thousand, five hundred twenty-one".