66360021 has 16 divisors (see below), whose sum is σ = 108898944. Its totient is φ = 35002944.

The previous prime is 66360013. The next prime is 66360043. The reversal of 66360021 is 12006366.

It is not a de Polignac number, because 66360021 - 2³ = 66360013 is a prime.

It is a Curzon number.

It is a junction number, because it is equal to n+sod(n) for n = 66359973 and 66360000.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (66360001) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 121266 + ... + 121811.

It is an arithmetic number, because the mean of its divisors is an integer number (6806184).

Almost surely, 2^66360021 is an apocalyptic number.

It is an amenable number.

66360021 is a deficient number, since it is larger than the sum of its proper divisors (42538923).

66360021 is a wasteful number, since it uses less digits than its factorization.

66360021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 243100.

The product of its (nonzero) digits is 1296, while the sum is 24.

The square root of 66360021 is about 8146.1660307165. The cubic root of 66360021 is about 404.8574837681.

Adding to 66360021 its reverse (12006366), we get a palindrome (78366387).

The spelling of 66360021 in words is "sixty-six million, three hundred sixty thousand, twenty-one".