66603213 has 12 divisors (see below), whose sum is σ = 96305820. Its totient is φ = 44355456.

The previous prime is 66603211. The next prime is 66603233. The reversal of 66603213 is 31230666.

It can be written as a sum of positive squares in 2 ways, for example, as 1671849 + 64931364 = 1293^2 + 8058^2 .

It is not a de Polignac number, because 66603213 - 2¹ = 66603211 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 (66603211) 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, 6645 + ... + 13317.

It is an arithmetic number, because the mean of its divisors is an integer number (8025485).

Almost surely, 2^66603213 is an apocalyptic number.

It is an amenable number.

66603213 is a deficient number, since it is larger than the sum of its proper divisors (29702607).

66603213 is a wasteful number, since it uses less digits than its factorization.

66603213 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7788 (or 7785 counting only the distinct ones).

The product of its (nonzero) digits is 3888, while the sum is 27.

The square root of 66603213 is about 8161.0791565822. The cubic root of 66603213 is about 405.3514461953.

Adding to 66603213 its reverse (31230666), we get a palindrome (97833879).

The spelling of 66603213 in words is "sixty-six million, six hundred three thousand, two hundred thirteen".