66821323 has 2 divisors, whose sum is σ = 66821324. Its totient is φ = 66821322.

The previous prime is 66821317. The next prime is 66821327. The reversal of 66821323 is 32312866.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 66821323 - 2⁹ = 66820811 is a prime.

It is not a weakly prime, because it can be changed into another prime (66821327) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 33410661 + 33410662.

It is an arithmetic number, because the mean of its divisors is an integer number (33410662).

Almost surely, 2^66821323 is an apocalyptic number.

66821323 is a deficient number, since it is larger than the sum of its proper divisors (1).

66821323 is an equidigital number, since it uses as much as digits as its factorization.

66821323 is an evil number, because the sum of its binary digits is even.

The product of its digits is 10368, while the sum is 31.

The square root of 66821323 is about 8174.4310505380. The cubic root of 66821323 is about 405.7934412406.

The spelling of 66821323 in words is "sixty-six million, eight hundred twenty-one thousand, three hundred twenty-three".