51131533549 has 2 divisors, whose sum is σ = 51131533550. Its totient is φ = 51131533548.

The previous prime is 51131533547. The next prime is 51131533577. The reversal of 51131533549 is 94533513115.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 35487777924 + 15643755625 = 188382^2 + 125075^2 .

It is a cyclic number.

It is not a de Polignac number, because 51131533549 - 2¹ = 51131533547 is a prime.

It is a super-2 number, since 2×51131533549² (a number of 22 digits) contains 22 as substring.

Together with 51131533547, it forms a pair of twin primes.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (51131533547) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 25565766774 + 25565766775.

It is an arithmetic number, because the mean of its divisors is an integer number (25565766775).

Almost surely, 2^51131533549 is an apocalyptic number.

It is an amenable number.

51131533549 is a deficient number, since it is larger than the sum of its proper divisors (1).

51131533549 is an equidigital number, since it uses as much as digits as its factorization.

51131533549 is an evil number, because the sum of its binary digits is even.

The product of its digits is 121500, while the sum is 40.

The spelling of 51131533549 in words is "fifty-one billion, one hundred thirty-one million, five hundred thirty-three thousand, five hundred forty-nine".