61318185840 has 200 divisors, whose sum is σ = 222227124768. Its totient is φ = 15640542720.

The previous prime is 61318185839. The next prime is 61318185883. The reversal of 61318185840 is 4858181316.

61318185840 is a `hidden beast` number, since 61 + 3 + 1 + 8 + 1 + 8 + 584 + 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 pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 39 ways as a sum of consecutive naturals, for example, 56671 + ... + 354750.

Almost surely, 2^61318185840 is an apocalyptic number.

61318185840 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 61318185840, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (111113562384).

61318185840 is an abundant number, since it is smaller than the sum of its proper divisors (160908938928).

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

61318185840 is a wasteful number, since it uses less digits than its factorization.

61318185840 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 411469 (or 411454 counting only the distinct ones).

The product of its (nonzero) digits is 184320, while the sum is 45.

The spelling of 61318185840 in words is "sixty-one billion, three hundred eighteen million, one hundred eighty-five thousand, eight hundred forty".