51942379081 has 4 divisors (see below), whose sum is σ = 52456660164. Its totient is φ = 51428098000.

The previous prime is 51942379067. The next prime is 51942379121. The reversal of 51942379081 is 18097324915.

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 26179240000 + 25763139081 = 161800^2 + 160509^2 .

It is a cyclic number.

It is not a de Polignac number, because 51942379081 - 2²¹ = 51940281929 is a prime.

It is a super-2 number, since 2×51942379081² (a number of 22 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (51942379381) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 257140390 + ... + 257140591.

It is an arithmetic number, because the mean of its divisors is an integer number (13114165041).

Almost surely, 2^51942379081 is an apocalyptic number.

It is an amenable number.

51942379081 is a deficient number, since it is larger than the sum of its proper divisors (514281083).

51942379081 is a wasteful number, since it uses less digits than its factorization.

51942379081 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 514281082.

The product of its (nonzero) digits is 544320, while the sum is 49.

The spelling of 51942379081 in words is "fifty-one billion, nine hundred forty-two million, three hundred seventy-nine thousand, eighty-one".