66753121 has 2 divisors, whose sum is σ = 66753122. Its totient is φ = 66753120.

The previous prime is 66753119. The next prime is 66753139. The reversal of 66753121 is 12135766.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 45037521 + 21715600 = 6711^2 + 4660^2 .

It is a cyclic number.

It is not a de Polignac number, because 66753121 - 2¹ = 66753119 is a prime.

Together with 66753119, it forms a pair of twin primes.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (66753151) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 33376560 + 33376561.

It is an arithmetic number, because the mean of its divisors is an integer number (33376561).

Almost surely, 2^66753121 is an apocalyptic number.

It is an amenable number.

66753121 is a deficient number, since it is larger than the sum of its proper divisors (1).

66753121 is an equidigital number, since it uses as much as digits as its factorization.

66753121 is an evil number, because the sum of its binary digits is even.

The product of its digits is 7560, while the sum is 31.

The square root of 66753121 is about 8170.2583190496. The cubic root of 66753121 is about 405.6553348981.

Adding to 66753121 its reverse (12135766), we get a palindrome (78888887).

The spelling of 66753121 in words is "sixty-six million, seven hundred fifty-three thousand, one hundred twenty-one".