12528777881 has 4 divisors (see below), whose sum is σ = 12608579172. Its totient is φ = 12448976592.

The previous prime is 12528777869. The next prime is 12528777883. The reversal of 12528777881 is 18877782521.

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 5849802256 + 6678975625 = 76484^2 + 81725^2 .

It is a cyclic number.

It is not a de Polignac number, because 12528777881 - 2⁶ = 12528777817 is a prime.

It is a super-2 number, since 2×12528777881² (a number of 21 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (12528777883) 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, 39900410 + ... + 39900723.

It is an arithmetic number, because the mean of its divisors is an integer number (3152144793).

Almost surely, 2^12528777881 is an apocalyptic number.

It is an amenable number.

12528777881 is a deficient number, since it is larger than the sum of its proper divisors (79801291).

12528777881 is an equidigital number, since it uses as much as digits as its factorization.

12528777881 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 79801290.

The product of its digits is 3512320, while the sum is 56.

The spelling of 12528777881 in words is "twelve billion, five hundred twenty-eight million, seven hundred seventy-seven thousand, eight hundred eighty-one".