66335021 has 4 divisors (see below), whose sum is σ = 66857472. Its totient is φ = 65812572.

The previous prime is 66334997. The next prime is 66335047. The reversal of 66335021 is 12053366.

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 a de Polignac number, because none of the positive numbers 2^k-66335021 is a prime.

It is a super-2 number, since 2×66335021² = 8800670022140882, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (66335051) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 261035 + ... + 261288.

It is an arithmetic number, because the mean of its divisors is an integer number (16714368).

Almost surely, 2^66335021 is an apocalyptic number.

It is an amenable number.

66335021 is a deficient number, since it is larger than the sum of its proper divisors (522451).

66335021 is a wasteful number, since it uses less digits than its factorization.

66335021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 522450.

The product of its (nonzero) digits is 3240, while the sum is 26.

The square root of 66335021 is about 8144.6314219859. The cubic root of 66335021 is about 404.8066363440.

Adding to 66335021 its reverse (12053366), we get a palindrome (78388387).

The spelling of 66335021 in words is "sixty-six million, three hundred thirty-five thousand, twenty-one".