66030021 has 12 divisors (see below), whose sum is σ = 96269472. Its totient is φ = 43607976.

The previous prime is 66030007. The next prime is 66030047. The reversal of 66030021 is 12003066.

It is a happy number.

66030021 is a `hidden beast` number, since 660 + 3 + 0 + 0 + 2 + 1 = 666.

It is not a de Polignac number, because 66030021 - 2⁷ = 66029893 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 66029976 and 66030003.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (66030001) 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, 33321 + ... + 35246.

It is an arithmetic number, because the mean of its divisors is an integer number (8022456).

Almost surely, 2^66030021 is an apocalyptic number.

It is an amenable number.

66030021 is a deficient number, since it is larger than the sum of its proper divisors (30239451).

66030021 is a wasteful number, since it uses less digits than its factorization.

66030021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 68680 (or 68677 counting only the distinct ones).

The product of its (nonzero) digits is 216, while the sum is 18.

The square root of 66030021 is about 8125.8858594002. The cubic root of 66030021 is about 404.1852665452.

Adding to 66030021 its reverse (12003066), we get a palindrome (78033087).

The spelling of 66030021 in words is "sixty-six million, thirty thousand, twenty-one".