65667644 has 36 divisors (see below), whose sum is σ = 135404640. Its totient is φ = 27780480.

The previous prime is 65667643. The next prime is 65667653. The reversal of 65667644 is 44676656.

It is a junction number, because it is equal to n+sod(n) for n = 65667595 and 65667604.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (65667643) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 13364 + ... + 17604.

It is an arithmetic number, because the mean of its divisors is an integer number (3761240).

Almost surely, 2^65667644 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 65667644, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (67702320).

65667644 is an abundant number, since it is smaller than the sum of its proper divisors (69736996).

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

65667644 is a wasteful number, since it uses less digits than its factorization.

65667644 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4338 (or 4329 counting only the distinct ones).

The product of its digits is 725760, while the sum is 44.

The square root of 65667644 is about 8103.5574903866. The cubic root of 65667644 is about 403.4445115423. Note that the first 3 decimals are identical.

The spelling of 65667644 in words is "sixty-five million, six hundred sixty-seven thousand, six hundred forty-four".