81610560 has 168 divisors, whose sum is σ = 287670240. Its totient is φ = 21224448.

The previous prime is 81610537. The next prime is 81610561. The reversal of 81610560 is 6501618.

81610560 = T₁₅₀ + T₁₅₁ + ... + T₇₈₉.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81610561) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 123511 + ... + 124169.

Almost surely, 2^81610560 is an apocalyptic number.

81610560 is a gapful number since it is divisible by the number (80) 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 81610560, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (143835120).

81610560 is an abundant number, since it is smaller than the sum of its proper divisors (206059680).

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

81610560 is a wasteful number, since it uses less digits than its factorization.

81610560 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 725 (or 712 counting only the distinct ones).

The product of its (nonzero) digits is 1440, while the sum is 27.

The square root of 81610560 is about 9033.8563194242. The cubic root of 81610560 is about 433.7592866208.

The spelling of 81610560 in words is "eighty-one million, six hundred ten thousand, five hundred sixty".