66649361 has 2 divisors, whose sum is σ = 66649362. Its totient is φ = 66649360.

The previous prime is 66649357. The next prime is 66649381. The reversal of 66649361 is 16394666.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 42981136 + 23668225 = 6556^2 + 4865^2 .

It is a cyclic number.

It is not a de Polignac number, because 66649361 - 2² = 66649357 is a prime.

It is a super-3 number, since 3×66649361³ (a number of 24 digits) contains 333 as substring.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (66649301) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 33324680 + 33324681.

It is an arithmetic number, because the mean of its divisors is an integer number (33324681).

Almost surely, 2^66649361 is an apocalyptic number.

It is an amenable number.

66649361 is a deficient number, since it is larger than the sum of its proper divisors (1).

66649361 is an equidigital number, since it uses as much as digits as its factorization.

66649361 is an evil number, because the sum of its binary digits is even.

The product of its digits is 139968, while the sum is 41.

The square root of 66649361 is about 8163.9059891696. The cubic root of 66649361 is about 405.4450444818.

The spelling of 66649361 in words is "sixty-six million, six hundred forty-nine thousand, three hundred sixty-one".