1213820 has 24 divisors (see below), whose sum is σ = 2573424. Its totient is φ = 480896.

The previous prime is 1213801. The next prime is 1213829. The reversal of 1213820 is 283121.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1213829) 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, 2519 + ... + 2961.

It is an arithmetic number, because the mean of its divisors is an integer number (107226).

2^1213820 is an apocalyptic number.

1213820 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

1213820 is an abundant number, since it is smaller than the sum of its proper divisors (1359604).

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

1213820 is a wasteful number, since it uses less digits than its factorization.

1213820 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 589 (or 587 counting only the distinct ones).

The product of its (nonzero) digits is 96, while the sum is 17.

The square root of 1213820 is about 1101.7349953596. The cubic root of 1213820 is about 106.6722436320.

Adding to 1213820 its reverse (283121), we get a palindrome (1496941).

The spelling of 1213820 in words is "one million, two hundred thirteen thousand, eight hundred twenty".