66867021 has 24 divisors (see below), whose sum is σ = 106442336. Its totient is φ = 40188960.

The previous prime is 66867013. The next prime is 66867037. The reversal of 66867021 is 12076866.

It is a happy number.

It is not a de Polignac number, because 66867021 - 2³ = 66867013 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (66867071) 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 23 ways as a sum of consecutive naturals, for example, 1615 + ... + 11676.

Almost surely, 2^66867021 is an apocalyptic number.

It is an amenable number.

66867021 is a deficient number, since it is larger than the sum of its proper divisors (39575315).

66867021 is a wasteful number, since it uses less digits than its factorization.

66867021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 13353 (or 13350 counting only the distinct ones).

The product of its (nonzero) digits is 24192, while the sum is 36.

The square root of 66867021 is about 8177.2257520506. The cubic root of 66867021 is about 405.8859253068.

The spelling of 66867021 in words is "sixty-six million, eight hundred sixty-seven thousand, twenty-one".