66556297 has 4 divisors (see below), whose sum is σ = 70059280. Its totient is φ = 63053316.

The previous prime is 66556291. The next prime is 66556327. The reversal of 66556297 is 79265566.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also an emirpimes, since its reverse is a distinct semiprime: 79265566 = 2 ⋅39632783.

It is a cyclic number.

It is not a de Polignac number, because 66556297 - 2¹⁹ = 66032009 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (66556291) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1751463 + ... + 1751500.

It is an arithmetic number, because the mean of its divisors is an integer number (17514820).

Almost surely, 2^66556297 is an apocalyptic number.

It is an amenable number.

66556297 is a deficient number, since it is larger than the sum of its proper divisors (3502983).

66556297 is a wasteful number, since it uses less digits than its factorization.

66556297 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3502982.

The product of its digits is 680400, while the sum is 46.

The square root of 66556297 is about 8158.2042754518. The cubic root of 66556297 is about 405.2562459054.

The spelling of 66556297 in words is "sixty-six million, five hundred fifty-six thousand, two hundred ninety-seven".