66021617 has 4 divisors (see below), whose sum is σ = 66050160. Its totient is φ = 65993076.

The previous prime is 66021611. The next prime is 66021629. The reversal of 66021617 is 71612066.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 66021617 - 2⁴ = 66021601 is a prime.

It is a super-3 number, since 3×66021617³ (a number of 24 digits) contains 333 as substring. Note that it is a super-d number also for d = 2.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 66021617.

It is not an unprimeable number, because it can be changed into a prime (66021611) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 10463 + ... + 15540.

It is an arithmetic number, because the mean of its divisors is an integer number (16512540).

Almost surely, 2^66021617 is an apocalyptic number.

It is an amenable number.

66021617 is a deficient number, since it is larger than the sum of its proper divisors (28543).

66021617 is a wasteful number, since it uses less digits than its factorization.

66021617 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 28542.

The product of its (nonzero) digits is 3024, while the sum is 29.

The square root of 66021617 is about 8125.3687300947. The cubic root of 66021617 is about 404.1681181984.

The spelling of 66021617 in words is "sixty-six million, twenty-one thousand, six hundred seventeen".