66852021 has 8 divisors (see below), whose sum is σ = 89362144. Its totient is φ = 44454960.

The previous prime is 66851987. The next prime is 66852029. The reversal of 66852021 is 12025866.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 66852021 - 2⁷ = 66851893 is a prime.

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 66852021.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (66852029) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 26875 + ... + 29256.

It is an arithmetic number, because the mean of its divisors is an integer number (11170268).

Almost surely, 2^66852021 is an apocalyptic number.

It is an amenable number.

66852021 is a deficient number, since it is larger than the sum of its proper divisors (22510123).

66852021 is a wasteful number, since it uses less digits than its factorization.

66852021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 56531.

The product of its (nonzero) digits is 5760, while the sum is 30.

The square root of 66852021 is about 8176.3085191301. The cubic root of 66852021 is about 405.8555728047.

Adding to 66852021 its reverse (12025866), we get a palindrome (78877887).

The spelling of 66852021 in words is "sixty-six million, eight hundred fifty-two thousand, twenty-one".