51966540 has 144 divisors (see below), whose sum is σ = 166333440. Its totient is φ = 13115520.

The previous prime is 51966517. The next prime is 51966547. The reversal of 51966540 is 4566915.

51966540 is a `hidden beast` number, since 51 + 9 + 66 + 540 = 666.

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

It is a junction number, because it is equal to n+sod(n) for n = 51966495 and 51966504.

It is not an unprimeable number, because it can be changed into a prime (51966547) by changing a digit.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 373791 + ... + 373929.

Almost surely, 2^51966540 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 51966540, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (83166720).

51966540 is an abundant number, since it is smaller than the sum of its proper divisors (114366900).

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

51966540 is a wasteful number, since it uses less digits than its factorization.

51966540 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 252 (or 247 counting only the distinct ones).

The product of its (nonzero) digits is 32400, while the sum is 36.

The square root of 51966540 is about 7208.7821440241. The cubic root of 51966540 is about 373.1710409252.

The spelling of 51966540 in words is "fifty-one million, nine hundred sixty-six thousand, five hundred forty".