66602813 has 2 divisors, whose sum is σ = 66602814. Its totient is φ = 66602812.

The previous prime is 66602803. The next prime is 66602831. The reversal of 66602813 is 31820666.

Together with next prime (66602831) it forms an Ormiston pair, because they use the same digits, order apart.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 66227044 + 375769 = 8138^2 + 613^2 .

It is a cyclic number.

It is not a de Polignac number, because 66602813 - 2⁶ = 66602749 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 66602813.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (66602803) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 33301406 + 33301407.

It is an arithmetic number, because the mean of its divisors is an integer number (33301407).

Almost surely, 2^66602813 is an apocalyptic number.

It is an amenable number.

66602813 is a deficient number, since it is larger than the sum of its proper divisors (1).

66602813 is an equidigital number, since it uses as much as digits as its factorization.

66602813 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 10368, while the sum is 32.

The square root of 66602813 is about 8161.0546499824. The cubic root of 66602813 is about 405.3506347184.

The spelling of 66602813 in words is "sixty-six million, six hundred two thousand, eight hundred thirteen".