66253733521 has 8 divisors (see below), whose sum is σ = 66811852800. Its totient is φ = 65696407920.

The previous prime is 66253733503. The next prime is 66253733591. The reversal of 66253733521 is 12533735266.

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 66253733521 - 2⁵ = 66253733489 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (66253733501) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 30166 + ... + 365263.

It is an arithmetic number, because the mean of its divisors is an integer number (8351481600).

Almost surely, 2^66253733521 is an apocalyptic number.

It is an amenable number.

66253733521 is a deficient number, since it is larger than the sum of its proper divisors (558119279).

66253733521 is a wasteful number, since it uses less digits than its factorization.

66253733521 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 396839.

The product of its digits is 680400, while the sum is 43.

The spelling of 66253733521 in words is "sixty-six billion, two hundred fifty-three million, seven hundred thirty-three thousand, five hundred twenty-one".