51171940 has 48 divisors (see below), whose sum is σ = 113742720. Its totient is φ = 19284480.

The previous prime is 51171893. The next prime is 51171943. The reversal of 51171940 is 4917115.

It is a junction number, because it is equal to n+sod(n) for n = 51171899 and 51171908.

It is not an unprimeable number, because it can be changed into a prime (51171943) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 117964 + ... + 118396.

It is an arithmetic number, because the mean of its divisors is an integer number (2369640).

Almost surely, 2^51171940 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 51171940, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (56871360).

51171940 is an abundant number, since it is smaller than the sum of its proper divisors (62570780).

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

51171940 is a wasteful number, since it uses less digits than its factorization.

51171940 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 772 (or 770 counting only the distinct ones).

The product of its (nonzero) digits is 1260, while the sum is 28.

The square root of 51171940 is about 7153.4565071719. The cubic root of 51171940 is about 371.2592594062.

It can be divided in two parts, 51 and 171940, that added together give a triangular number (171991 = T₅₈₆).

The spelling of 51171940 in words is "fifty-one million, one hundred seventy-one thousand, nine hundred forty".