51489561600 has 924 divisors, whose sum is σ = 199752482880. Its totient is φ = 13138329600.

The previous prime is 51489561559. The next prime is 51489561661. The reversal of 51489561600 is 616598415.

51489561600 is a `hidden beast` number, since 5 + 1 + 4 + 89 + 561 + 6 + 0 + 0 = 666.

It is a Harshad number since it is a multiple of its sum of digits (45).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 83 ways as a sum of consecutive naturals, for example, 578534356 + ... + 578534444.

Almost surely, 2^51489561600 is an apocalyptic number.

51489561600 is a gapful number since it is divisible by the number (50) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 51489561600, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (99876241440).

51489561600 is an abundant number, since it is smaller than the sum of its proper divisors (148262921280).

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

51489561600 is an equidigital number, since it uses as much as digits as its factorization.

51489561600 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 168 (or 130 counting only the distinct ones).

The product of its (nonzero) digits is 259200, while the sum is 45.

It can be divided in two parts, 51489 and 561600, that added together give a square (613089 = 783²).

The spelling of 51489561600 in words is "fifty-one billion, four hundred eighty-nine million, five hundred sixty-one thousand, six hundred".