12511331533 has 4 divisors (see below), whose sum is σ = 12542846620. Its totient is φ = 12479816448.

The previous prime is 12511331513. The next prime is 12511331537. The reversal of 12511331533 is 33513311521.

It is a happy number.

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 11029620484 + 1481711049 = 105022^2 + 38493^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-12511331533 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (12511331537) 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, 15756948 + ... + 15757741.

It is an arithmetic number, because the mean of its divisors is an integer number (3135711655).

Almost surely, 2^12511331533 is an apocalyptic number.

It is an amenable number.

12511331533 is a deficient number, since it is larger than the sum of its proper divisors (31515087).

12511331533 is an equidigital number, since it uses as much as digits as its factorization.

12511331533 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 31515086.

The product of its digits is 4050, while the sum is 28.

The spelling of 12511331533 in words is "twelve billion, five hundred eleven million, three hundred thirty-one thousand, five hundred thirty-three".