51556789440 has 1344 divisors, whose sum is σ = 218472837120. Its totient is φ = 11386552320.

The previous prime is 51556789381. The next prime is 51556789447. The reversal of 51556789440 is 4498765515.

It is a happy number.

51556789440 is a `hidden beast` number, since 5 + 1 + 556 + 7 + 89 + 4 + 4 + 0 = 666.

It is a Harshad number since it is a multiple of its sum of digits (54).

It is not an unprimeable number, because it can be changed into a prime (51556789447) by changing a digit.

It is a polite number, since it can be written in 191 ways as a sum of consecutive naturals, for example, 769504287 + ... + 769504353.

Almost surely, 2^51556789440 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 51556789440, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (109236418560).

51556789440 is an abundant number, since it is smaller than the sum of its proper divisors (166916047680).

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

51556789440 is a wasteful number, since it uses less digits than its factorization.

51556789440 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 167 (or 138 counting only the distinct ones).

The product of its (nonzero) digits is 6048000, while the sum is 54.

The spelling of 51556789440 in words is "fifty-one billion, five hundred fifty-six million, seven hundred eighty-nine thousand, four hundred forty".