66284657288521 has 9 divisors (see below), whose sum is σ = 77106708447399. Its totient is φ = 56815371683784.

The previous prime is 66284657288461. The next prime is 66284657288527. The reversal of 66284657288521 is 12588275648266.

The square root of 66284657288521 is 8141539.

It is a perfect power (a square), and thus also a powerful number.

It can be written as a sum of positive squares in only one way, i.e., 60282525625 + 66224374762896 = 245525^2 + 8137836^2 .

It is not a de Polignac number, because 66284657288521 - 2⁹ = 66284657288009 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (66284657288527) by changing a digit.

It is a polite number, since it can be written in 8 ways as a sum of consecutive naturals, for example, 56409235 + ... + 57572311.

It is an arithmetic number, because the mean of its divisors is an integer number (8567412049711).

Almost surely, 2^{66284657288521} is an apocalyptic number.

66284657288521 is the 8141539-th square number.

66284657288521 is the 4070770-th centered octagonal number.

It is an amenable number.

66284657288521 is a deficient number, since it is larger than the sum of its proper divisors (10822051158878).

66284657288521 is an frugal number, since it uses more digits than its factorization.

66284657288521 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2326168 (or 1163084 counting only the distinct ones).

The product of its digits is 619315200, while the sum is 70.

The spelling of 66284657288521 in words is "sixty-six trillion, two hundred eighty-four billion, six hundred fifty-seven million, two hundred eighty-eight thousand, five hundred twenty-one".