1221888 has 72 divisors (see below), whose sum is σ = 3417568. Its totient is φ = 387072.

The previous prime is 1221863. The next prime is 1221907. The reversal of 1221888 is 8881221.

It is a nude number because it is divisible by every one of its digits.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 28395 + ... + 28437.

2^1221888 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 1221888, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1708784).

1221888 is an abundant number, since it is smaller than the sum of its proper divisors (2195680).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

1221888 is an equidigital number, since it uses as much as digits as its factorization.

1221888 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 99 (or 85 counting only the distinct ones).

The product of its digits is 2048, while the sum is 30.

The square root of 1221888 is about 1105.3904287626. The cubic root of 1221888 is about 106.9080643909.

The spelling of 1221888 in words is "one million, two hundred twenty-one thousand, eight hundred eighty-eight".