66823397 has 8 divisors (see below), whose sum is σ = 68444376. Its totient is φ = 65221632.

The previous prime is 66823381. The next prime is 66823409. The reversal of 66823397 is 79332866.

It can be written as a sum of positive squares in 4 ways, for example, as 11930116 + 54893281 = 3454^2 + 7409^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 66823397 - 2⁴ = 66823381 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (66823327) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 2363 + ... + 11799.

It is an arithmetic number, because the mean of its divisors is an integer number (8555547).

Almost surely, 2^66823397 is an apocalyptic number.

It is an amenable number.

66823397 is a deficient number, since it is larger than the sum of its proper divisors (1620979).

66823397 is an equidigital number, since it uses as much as digits as its factorization.

66823397 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9607.

The product of its digits is 326592, while the sum is 44.

The square root of 66823397 is about 8174.5579085355. The cubic root of 66823397 is about 405.7976395356.

It can be divided in two parts, 668233 and 97, that multiplied together give a square (64818601 = 8051²).

The spelling of 66823397 in words is "sixty-six million, eight hundred twenty-three thousand, three hundred ninety-seven".