1213720 has 32 divisors (see below), whose sum is σ = 2876400. Its totient is φ = 459648.

The previous prime is 1213673. The next prime is 1213721. The reversal of 1213720 is 273121.

It is a happy number.

It is a junction number, because it is equal to n+sod(n) for n = 1213694 and 1213703.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1213721) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 39 + ... + 1558.

2^1213720 is an apocalyptic number.

1213720 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 1213720, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1438200).

1213720 is an abundant number, since it is smaller than the sum of its proper divisors (1662680).

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

1213720 is a wasteful number, since it uses less digits than its factorization.

1213720 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1627 (or 1623 counting only the distinct ones).

The product of its (nonzero) digits is 84, while the sum is 16.

The square root of 1213720 is about 1101.6896114605. The cubic root of 1213720 is about 106.6693141704.

Adding to 1213720 its reverse (273121), we get a palindrome (1486841).

The spelling of 1213720 in words is "one million, two hundred thirteen thousand, seven hundred twenty".