66523240021 has 8 divisors (see below), whose sum is σ = 80027958080. Its totient is φ = 54018871488.

The previous prime is 66523239943. The next prime is 66523240061. The reversal of 66523240021 is 12004232566.

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

It is a cyclic number.

It is not a de Polignac number, because 66523240021 - 2⁹ = 66523239509 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (66523240061) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 250087236 + ... + 250087501.

It is an arithmetic number, because the mean of its divisors is an integer number (10003494760).

Almost surely, 2^66523240021 is an apocalyptic number.

It is an amenable number.

66523240021 is a deficient number, since it is larger than the sum of its proper divisors (13504718059).

66523240021 is a wasteful number, since it uses less digits than its factorization.

66523240021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 500174763.

The product of its (nonzero) digits is 17280, while the sum is 31.

Adding to 66523240021 its reverse (12004232566), we get a palindrome (78527472587).

The spelling of 66523240021 in words is "sixty-six billion, five hundred twenty-three million, two hundred forty thousand, twenty-one".