1221908 has 6 divisors (see below), whose sum is σ = 2138346. Its totient is φ = 610952.

The previous prime is 1221907. The next prime is 1221917. The reversal of 1221908 is 8091221.

It can be written as a sum of positive squares in only one way, i.e., 743044 + 478864 = 862^2 + 692^2 .

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1221907) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 152735 + ... + 152742.

It is an arithmetic number, because the mean of its divisors is an integer number (356391).

2^1221908 is an apocalyptic number.

It is an amenable number.

1221908 is a deficient number, since it is larger than the sum of its proper divisors (916438).

1221908 is a wasteful number, since it uses less digits than its factorization.

1221908 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 305481 (or 305479 counting only the distinct ones).

The product of its (nonzero) digits is 288, while the sum is 23.

The square root of 1221908 is about 1105.3994753029. The cubic root of 1221908 is about 106.9086476821.

The spelling of 1221908 in words is "one million, two hundred twenty-one thousand, nine hundred eight".