66822817 has 4 divisors (see below), whose sum is σ = 68376880. Its totient is φ = 65268756.

The previous prime is 66822803. The next prime is 66822823. The reversal of 66822817 is 71822866.

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.

It is a cyclic number.

It is not a de Polignac number, because 66822817 - 2⁷ = 66822689 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 66822817.

It is not an unprimeable number, because it can be changed into a prime (66822317) 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, 776967 + ... + 777052.

It is an arithmetic number, because the mean of its divisors is an integer number (17094220).

Almost surely, 2^66822817 is an apocalyptic number.

It is an amenable number.

66822817 is a deficient number, since it is larger than the sum of its proper divisors (1554063).

66822817 is a wasteful number, since it uses less digits than its factorization.

66822817 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1554062.

The product of its digits is 64512, while the sum is 40.

The square root of 66822817 is about 8174.5224325339. The cubic root of 66822817 is about 405.7964654792.

The spelling of 66822817 in words is "sixty-six million, eight hundred twenty-two thousand, eight hundred seventeen".