1221240 has 32 divisors (see below), whose sum is σ = 3664080. Its totient is φ = 325632.

The previous prime is 1221239. The next prime is 1221247. The reversal of 1221240 is 421221.

It is a Harshad number since it is a multiple of its sum of digits (12).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1221247) 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, 4969 + ... + 5208.

2^1221240 is an apocalyptic number.

1221240 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

1221240 is an abundant number, since it is smaller than the sum of its proper divisors (2442840).

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

1221240 is a wasteful number, since it uses less digits than its factorization.

1221240 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10191 (or 10187 counting only the distinct ones).

The product of its (nonzero) digits is 32, while the sum is 12.

The square root of 1221240 is about 1105.0972807857. The cubic root of 1221240 is about 106.8891623105.

Adding to 1221240 its reverse (421221), we get a palindrome (1642461).

The spelling of 1221240 in words is "one million, two hundred twenty-one thousand, two hundred forty".