1121720 has 32 divisors (see below), whose sum is σ = 2613600. Its totient is φ = 432768.

The previous prime is 1121707. The next prime is 1121723. The reversal of 1121720 is 271211.

It is a junction number, because it is equal to n+sod(n) for n = 1121695 and 1121704.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1121723) 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, 677 + ... + 1643.

It is an arithmetic number, because the mean of its divisors is an integer number (81675).

2^1121720 is an apocalyptic number.

1121720 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 1121720, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1306800).

1121720 is an abundant number, since it is smaller than the sum of its proper divisors (1491880).

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

1121720 is a wasteful number, since it uses less digits than its factorization.

1121720 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1007 (or 1003 counting only the distinct ones).

The product of its (nonzero) digits is 28, while the sum is 14.

The square root of 1121720 is about 1059.1128362927. The cubic root of 1121720 is about 103.9030160959.

Adding to 1121720 its reverse (271211), we get a palindrome (1392931).

The spelling of 1121720 in words is "one million, one hundred twenty-one thousand, seven hundred twenty".