81350560 has 48 divisors (see below), whose sum is σ = 196894152. Its totient is φ = 31744000.

The previous prime is 81350537. The next prime is 81350579. The reversal of 81350560 is 6505318.

It can be written as a sum of positive squares in 4 ways, for example, as 38787984 + 42562576 = 6228^2 + 6524^2 .

It is a super-2 number, since 2×81350560² = 13235827224627200, which contains 22 as substring.

It is a Smith number, since the sum of its digits (28) coincides with the sum of the digits of its prime factors.

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 7 ways as a sum of consecutive naturals, for example, 360 + ... + 12760.

Almost surely, 2^81350560 is an apocalyptic number.

81350560 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 81350560, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (98447076).

81350560 is an abundant number, since it is smaller than the sum of its proper divisors (115543592).

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

81350560 is a wasteful number, since it uses less digits than its factorization.

81350560 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 12457 (or 12449 counting only the distinct ones).

The product of its (nonzero) digits is 3600, while the sum is 28.

The square root of 81350560 is about 9019.4545289613. The cubic root of 81350560 is about 433.2981641412.

Adding to 81350560 its reverse (6505318), we get a palindrome (87855878).

The spelling of 81350560 in words is "eighty-one million, three hundred fifty thousand, five hundred sixty".