51071246820 has 252 divisors, whose sum is σ = 176754167100. Its totient is φ = 12380480640.

The previous prime is 51071246797. The next prime is 51071246873. The reversal of 51071246820 is 2864217015.

It can be written as a sum of positive squares in 2 ways, for example, as 39125631204 + 11945615616 = 197802^2 + 109296^2 .

It is a super-2 number, since 2×51071246820² (a number of 22 digits) contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 83 ways as a sum of consecutive naturals, for example, 1749706 + ... + 1778654.

It is an arithmetic number, because the mean of its divisors is an integer number (701405425).

Almost surely, 2^51071246820 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 51071246820, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (88377083550).

51071246820 is an abundant number, since it is smaller than the sum of its proper divisors (125682920280).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

51071246820 is a wasteful number, since it uses less digits than its factorization.

51071246820 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 28998 (or 28970 counting only the distinct ones).

The product of its (nonzero) digits is 26880, while the sum is 36.

The spelling of 51071246820 in words is "fifty-one billion, seventy-one million, two hundred forty-six thousand, eight hundred twenty".