1221766 has 32 divisors (see below), whose sum is σ = 2318400. Its totient is φ = 479808.

The previous prime is 1221761. The next prime is 1221767. The reversal of 1221766 is 6671221.

It is a self number, because there is not a number n which added to its sum of digits gives 1221766.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1221761) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 8850 + ... + 8986.

It is an arithmetic number, because the mean of its divisors is an integer number (72450).

2^1221766 is an apocalyptic number.

1221766 is a deficient number, since it is larger than the sum of its proper divisors (1096634).

1221766 is a wasteful number, since it uses less digits than its factorization.

1221766 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 173 (or 159 counting only the distinct ones).

The product of its digits is 1008, while the sum is 25.

The square root of 1221766 is about 1105.3352432633. The cubic root of 1221766 is about 106.9045061766.

Adding to 1221766 its reverse (6671221), we get a palindrome (7892987).

The spelling of 1221766 in words is "one million, two hundred twenty-one thousand, seven hundred sixty-six".