65561280 has 112 divisors (see below), whose sum is σ = 214969344. Its totient is φ = 16911360.

The previous prime is 65561269. The next prime is 65561281. The reversal of 65561280 is 8216556.

It is not an unprimeable number, because it can be changed into a prime (65561281) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 28659 + ... + 30861.

Almost surely, 2^65561280 is an apocalyptic number.

65561280 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 65561280, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (107484672).

65561280 is an abundant number, since it is smaller than the sum of its proper divisors (149408064).

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

65561280 is a wasteful number, since it uses less digits than its factorization.

65561280 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2254 (or 2244 counting only the distinct ones).

The product of its (nonzero) digits is 14400, while the sum is 33.

The square root of 65561280 is about 8096.9920340828. The cubic root of 65561280 is about 403.2265698036.

The spelling of 65561280 in words is "sixty-five million, five hundred sixty-one thousand, two hundred eighty".