66524321 has 2 divisors, whose sum is σ = 66524322. Its totient is φ = 66524320.

The previous prime is 66524299. The next prime is 66524333. The reversal of 66524321 is 12342566.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 34939921 + 31584400 = 5911^2 + 5620^2 .

It is a cyclic number.

It is not a de Polignac number, because 66524321 - 2¹⁰ = 66523297 is a prime.

It is a super-2 number, since 2×66524321² = 8850970569022082, which contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (66524351) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 33262160 + 33262161.

It is an arithmetic number, because the mean of its divisors is an integer number (33262161).

Almost surely, 2^66524321 is an apocalyptic number.

It is an amenable number.

66524321 is a deficient number, since it is larger than the sum of its proper divisors (1).

66524321 is an equidigital number, since it uses as much as digits as its factorization.

66524321 is an evil number, because the sum of its binary digits is even.

The product of its digits is 8640, while the sum is 29.

The square root of 66524321 is about 8156.2442950172. The cubic root of 66524321 is about 405.1913356961.

Adding to 66524321 its reverse (12342566), we get a palindrome (78866887).

The spelling of 66524321 in words is "sixty-six million, five hundred twenty-four thousand, three hundred twenty-one".