51655240 has 128 divisors (see below), whose sum is σ = 149506560. Its totient is φ = 15611904.

The previous prime is 51655229. The next prime is 51655259. The reversal of 51655240 is 4255615.

It is a Harshad number since it is a multiple of its sum of digits (28).

It is a junction number, because it is equal to n+sod(n) for n = 51655199 and 51655208.

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, 83412 + ... + 84028.

It is an arithmetic number, because the mean of its divisors is an integer number (1168020).

Almost surely, 2^51655240 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 51655240, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (74753280).

51655240 is an abundant number, since it is smaller than the sum of its proper divisors (97851320).

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

51655240 is a wasteful number, since it uses less digits than its factorization.

51655240 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 671 (or 667 counting only the distinct ones).

The product of its (nonzero) digits is 6000, while the sum is 28.

The square root of 51655240 is about 7187.1579918630. The cubic root of 51655240 is about 372.4244009758.

The spelling of 51655240 in words is "fifty-one million, six hundred fifty-five thousand, two hundred forty".