1221388 has 24 divisors (see below), whose sum is σ = 2466464. Its totient is φ = 518400.

The previous prime is 1221383. The next prime is 1221391. The reversal of 1221388 is 8831221.

It is not an unprimeable number, because it can be changed into a prime (1221383) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 4948 + ... + 5188.

2^1221388 is an apocalyptic number.

It is an amenable number.

1221388 is an abundant number, since it is smaller than the sum of its proper divisors (1245076).

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

1221388 is a wasteful number, since it uses less digits than its factorization.

1221388 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 433 (or 431 counting only the distinct ones).

The product of its digits is 768, while the sum is 25.

The square root of 1221388 is about 1105.1642411877. The cubic root of 1221388 is about 106.8934800414.

The spelling of 1221388 in words is "one million, two hundred twenty-one thousand, three hundred eighty-eight".