51117128501 has 8 divisors (see below), whose sum is σ = 51824792664. Its totient is φ = 50409665280.

The previous prime is 51117128479. The next prime is 51117128509. The reversal of 51117128501 is 10582171115.

It can be written as a sum of positive squares in 4 ways, for example, as 13041411601 + 38075716900 = 114199^2 + 195130^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a de Polignac number, because none of the positive numbers 2^k-51117128501 is a prime.

It is a super-2 number, since 2×51117128501² (a number of 22 digits) contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (51117128509) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 504065 + ... + 596921.

It is an arithmetic number, because the mean of its divisors is an integer number (6478099083).

Almost surely, 2^51117128501 is an apocalyptic number.

It is an amenable number.

51117128501 is a deficient number, since it is larger than the sum of its proper divisors (707664163).

51117128501 is an equidigital number, since it uses as much as digits as its factorization.

51117128501 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 100471.

The product of its (nonzero) digits is 2800, while the sum is 32.

Adding to 51117128501 its reverse (10582171115), we get a palindrome (61699299616).

The spelling of 51117128501 in words is "fifty-one billion, one hundred seventeen million, one hundred twenty-eight thousand, five hundred one".