66213297 has 24 divisors (see below), whose sum is σ = 101088000. Its totient is φ = 41678208.

The previous prime is 66213253. The next prime is 66213299. The reversal of 66213297 is 79231266.

66213297 is a `hidden beast` number, since 6 + 621 + 3 + 29 + 7 = 666.

It is not a de Polignac number, because 66213297 - 2¹⁰ = 66212273 is a prime.

It is a super-2 number, since 2×66213297² = 8768401399220418, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (66213299) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 14329 + ... + 18377.

It is an arithmetic number, because the mean of its divisors is an integer number (4212000).

Almost surely, 2^66213297 is an apocalyptic number.

It is an amenable number.

66213297 is a deficient number, since it is larger than the sum of its proper divisors (34874703).

66213297 is a wasteful number, since it uses less digits than its factorization.

66213297 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4157 (or 4154 counting only the distinct ones).

The product of its digits is 27216, while the sum is 36.

The square root of 66213297 is about 8137.1553383231. The cubic root of 66213297 is about 404.5588795658.

The spelling of 66213297 in words is "sixty-six million, two hundred thirteen thousand, two hundred ninety-seven".