51271821180 has 96 divisors (see below), whose sum is σ = 159660110400. Its totient is φ = 13659819264.

The previous prime is 51271821169. The next prime is 51271821247. The reversal of 51271821180 is 8112817215.

It is a super-2 number, since 2×51271821180² (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 a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 546786 + ... + 633654.

It is an arithmetic number, because the mean of its divisors is an integer number (1663126150).

Almost surely, 2^51271821180 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 51271821180, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (79830055200).

51271821180 is an abundant number, since it is smaller than the sum of its proper divisors (108388289220).

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

51271821180 is a wasteful number, since it uses less digits than its factorization.

51271821180 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 87980 (or 87972 counting only the distinct ones).

The product of its (nonzero) digits is 8960, while the sum is 36.

The spelling of 51271821180 in words is "fifty-one billion, two hundred seventy-one million, eight hundred twenty-one thousand, one hundred eighty".