66040016563021 has 16 divisors (see below), whose sum is σ = 68355030706560. Its totient is φ = 63727530511680.

The previous prime is 66040016563009. The next prime is 66040016563217. The reversal of 66040016563021 is 12036561004066.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-66040016563021 is a prime.

It is a super-2 number, since 2×66040016563021² (a number of 28 digits) 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 (66040016563621) 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, 387717151 + ... + 387887443.

It is an arithmetic number, because the mean of its divisors is an integer number (4272189419160).

Almost surely, 2^{66040016563021} is an apocalyptic number.

It is an amenable number.

66040016563021 is a deficient number, since it is larger than the sum of its proper divisors (2315014143539).

66040016563021 is a wasteful number, since it uses less digits than its factorization.

66040016563021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 177636.

The product of its (nonzero) digits is 155520, while the sum is 40.

Adding to 66040016563021 its reverse (12036561004066), we get a palindrome (78076577567087).

The spelling of 66040016563021 in words is "sixty-six trillion, forty billion, sixteen million, five hundred sixty-three thousand, twenty-one".