65561408 has 56 divisors (see below), whose sum is σ = 148132800. Its totient is φ = 28497920.

The previous prime is 65561407. The next prime is 65561413. The reversal of 65561408 is 80416556.

It is a happy number.

It is a Cunningham number, because it is equal to 8097²-1.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (65561407) 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 7 ways as a sum of consecutive naturals, for example, 14168 + ... + 18216.

Almost surely, 2^65561408 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 65561408, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (74066400).

65561408 is an abundant number, since it is smaller than the sum of its proper divisors (82571392).

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

65561408 is a wasteful number, since it uses less digits than its factorization.

65561408 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4095 (or 4085 counting only the distinct ones).

The product of its (nonzero) digits is 28800, while the sum is 35.

The square root of 65561408 is about 8096.9999382487. Note that the first 4 decimals coincide. The cubic root of 65561408 is about 403.2268322195.

The spelling of 65561408 in words is "sixty-five million, five hundred sixty-one thousand, four hundred eight".