66206961 has 12 divisors (see below), whose sum is σ = 95847492. Its totient is φ = 44038656.

The previous prime is 66206957. The next prime is 66206969. The reversal of 66206961 is 16960266.

It is a happy number.

It can be written as a sum of positive squares in 2 ways, for example, as 48566961 + 17640000 = 6969^2 + 4200^2 .

It is not a de Polignac number, because 66206961 - 2² = 66206957 is a prime.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (66206969) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 3936 + ... + 12161.

It is an arithmetic number, because the mean of its divisors is an integer number (7987291).

Almost surely, 2^66206961 is an apocalyptic number.

It is an amenable number.

66206961 is a deficient number, since it is larger than the sum of its proper divisors (29640531).

66206961 is a wasteful number, since it uses less digits than its factorization.

66206961 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 16560 (or 16557 counting only the distinct ones).

The product of its (nonzero) digits is 23328, while the sum is 36.

The square root of 66206961 is about 8136.7660037634. The cubic root of 66206961 is about 404.5459749734.

The spelling of 66206961 in words is "sixty-six million, two hundred six thousand, nine hundred sixty-one".