61856455680 has 352 divisors, whose sum is σ = 232766498880. Its totient is φ = 15524167680.

The previous prime is 61856455679. The next prime is 61856455733. The reversal of 61856455680 is 8655465816.

61856455680 is a `hidden beast` number, since 6 + 1 + 8 + 5 + 6 + 4 + 556 + 80 = 666.

It is a super-2 number, since 2×61856455680² (a number of 22 digits) contains 22 as substring.

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

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 31 ways as a sum of consecutive naturals, for example, 2336920 + ... + 2363240.

Almost surely, 2^61856455680 is an apocalyptic number.

61856455680 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 61856455680, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (116383249440).

61856455680 is an abundant number, since it is smaller than the sum of its proper divisors (170910043200).

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

61856455680 is a wasteful number, since it uses less digits than its factorization.

61856455680 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 26372 (or 26348 counting only the distinct ones).

The product of its (nonzero) digits is 6912000, while the sum is 54.

The spelling of 61856455680 in words is "sixty-one billion, eight hundred fifty-six million, four hundred fifty-five thousand, six hundred eighty".