1228640 has 48 divisors (see below), whose sum is σ = 3320352. Its totient is φ = 420864.

The previous prime is 1228631. The next prime is 1228651. The reversal of 1228640 is 468221.

1228640 = T₃₅ + T₃₆ + ... + T₁₉₄.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 572 + ... + 1668.

It is an arithmetic number, because the mean of its divisors is an integer number (69174).

2^1228640 is an apocalyptic number.

1228640 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 1228640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1660176).

1228640 is an abundant number, since it is smaller than the sum of its proper divisors (2091712).

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

1228640 is a wasteful number, since it uses less digits than its factorization.

1228640 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1119 (or 1111 counting only the distinct ones).

The product of its (nonzero) digits is 768, while the sum is 23.

The square root of 1228640 is about 1108.4403457110. The cubic root of 1228640 is about 107.1046229714.

The spelling of 1228640 in words is "one million, two hundred twenty-eight thousand, six hundred forty".