66350621 has 2 divisors, whose sum is σ = 66350622. Its totient is φ = 66350620.

The previous prime is 66350611. The next prime is 66350639. The reversal of 66350621 is 12605366.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 51681721 + 14668900 = 7189^2 + 3830^2 .

It is a cyclic number.

It is not a de Polignac number, because 66350621 - 2¹⁰ = 66349597 is a prime.

It is a Chen prime.

It is equal to p_3915713 and since 66350621 and 3915713 have the same sum of digits, it is a Honaker prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (66350611) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 33175310 + 33175311.

It is an arithmetic number, because the mean of its divisors is an integer number (33175311).

Almost surely, 2^66350621 is an apocalyptic number.

It is an amenable number.

66350621 is a deficient number, since it is larger than the sum of its proper divisors (1).

66350621 is an equidigital number, since it uses as much as digits as its factorization.

66350621 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 6480, while the sum is 29.

The square root of 66350621 is about 8145.5890517506. The cubic root of 66350621 is about 404.8383666350.

Adding to 66350621 its reverse (12605366), we get a palindrome (78955987).

The spelling of 66350621 in words is "sixty-six million, three hundred fifty thousand, six hundred twenty-one".