61543318320 has 320 divisors, whose sum is σ = 232011578880. Its totient is φ = 14870707200.

The previous prime is 61543318289. The next prime is 61543318357. The reversal of 61543318320 is 2381334516.

61543318320 is a `hidden beast` number, since 6 + 1 + 543 + 31 + 83 + 2 + 0 = 666.

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

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 7527835 + ... + 7536005.

It is an arithmetic number, because the mean of its divisors is an integer number (725036184).

Almost surely, 2^61543318320 is an apocalyptic number.

61543318320 is a gapful number since it is divisible by the number (60) 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 61543318320, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (116005789440).

61543318320 is an abundant number, since it is smaller than the sum of its proper divisors (170468260560).

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

61543318320 is a wasteful number, since it uses less digits than its factorization.

61543318320 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 8521 (or 8509 counting only the distinct ones).

The product of its (nonzero) digits is 51840, while the sum is 36.

The spelling of 61543318320 in words is "sixty-one billion, five hundred forty-three million, three hundred eighteen thousand, three hundred twenty".