65606621 has 4 divisors (see below), whose sum is σ = 69465852. Its totient is φ = 61747392.

The previous prime is 65606599. The next prime is 65606623. The reversal of 65606621 is 12660656.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 43375396 + 22231225 = 6586^2 + 4715^2 .

It is a cyclic number.

It is not a de Polignac number, because 65606621 - 2²² = 61412317 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (65606623) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1929590 + ... + 1929623.

It is an arithmetic number, because the mean of its divisors is an integer number (17366463).

Almost surely, 2^65606621 is an apocalyptic number.

It is an amenable number.

65606621 is a deficient number, since it is larger than the sum of its proper divisors (3859231).

65606621 is a wasteful number, since it uses less digits than its factorization.

65606621 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3859230.

The product of its (nonzero) digits is 12960, while the sum is 32.

The square root of 65606621 is about 8099.7914170675. The cubic root of 65606621 is about 403.3195031268.

The spelling of 65606621 in words is "sixty-five million, six hundred six thousand, six hundred twenty-one".