66214321 has 2 divisors, whose sum is σ = 66214322. Its totient is φ = 66214320.

The previous prime is 66214307. The next prime is 66214327. The reversal of 66214321 is 12341266.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 63361600 + 2852721 = 7960^2 + 1689^2 .

It is a cyclic number.

It is not a de Polignac number, because 66214321 - 2⁹ = 66213809 is a prime.

It is not a weakly prime, because it can be changed into another prime (66214327) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 33107160 + 33107161.

It is an arithmetic number, because the mean of its divisors is an integer number (33107161).

Almost surely, 2^66214321 is an apocalyptic number.

It is an amenable number.

66214321 is a deficient number, since it is larger than the sum of its proper divisors (1).

66214321 is an equidigital number, since it uses as much as digits as its factorization.

66214321 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 1728, while the sum is 25.

The square root of 66214321 is about 8137.2182593316. The cubic root of 66214321 is about 404.5609650792.

Adding to 66214321 its reverse (12341266), we get a palindrome (78555587).

The spelling of 66214321 in words is "sixty-six million, two hundred fourteen thousand, three hundred twenty-one".