61181890560 has 312 divisors, whose sum is σ = 242372345280. Its totient is φ = 13984137216.

The previous prime is 61181890559. The next prime is 61181890571. The reversal of 61181890560 is 6509818116.

61181890560 is a `hidden beast` number, since 6 + 1 + 1 + 8 + 1 + 89 + 0 + 560 = 666.

It is a super-2 number, since 2×61181890560² (a number of 22 digits) contains 22 as substring.

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

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 1266531 + ... + 1313949.

It is an arithmetic number, because the mean of its divisors is an integer number (776834440).

Almost surely, 2^61181890560 is an apocalyptic number.

61181890560 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 61181890560, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (121186172640).

61181890560 is an abundant number, since it is smaller than the sum of its proper divisors (181190454720).

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

61181890560 is a wasteful number, since it uses less digits than its factorization.

61181890560 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 47461 (or 47436 counting only the distinct ones).

The product of its (nonzero) digits is 103680, while the sum is 45.

The spelling of 61181890560 in words is "sixty-one billion, one hundred eighty-one million, eight hundred ninety thousand, five hundred sixty".