1821223766 has 8 divisors (see below), whose sum is σ = 2850611184. Its totient is φ = 871020040.

The previous prime is 1821223757. The next prime is 1821223771. The reversal of 1821223766 is 6673221281.

It is a happy number.

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

It is a congruent number.

It is an unprimeable number.

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 3 ways as a sum of consecutive naturals, for example, 19795865 + ... + 19795956.

It is an arithmetic number, because the mean of its divisors is an integer number (356326398).

Almost surely, 2^1821223766 is an apocalyptic number.

1821223766 is a deficient number, since it is larger than the sum of its proper divisors (1029387418).

1821223766 is a wasteful number, since it uses less digits than its factorization.

1821223766 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 39591846.

The product of its digits is 48384, while the sum is 38.

The square root of 1821223766 is about 42675.7983639439. The cubic root of 1821223766 is about 1221.2027389085.

The spelling of 1821223766 in words is "one billion, eight hundred twenty-one million, two hundred twenty-three thousand, seven hundred sixty-six".