11121720 has 32 divisors (see below), whose sum is σ = 33365520. Its totient is φ = 2965760.

The previous prime is 11121713. The next prime is 11121731. The reversal of 11121720 is 2712111.

It is a Harshad number since it is a multiple of its sum of digits (15).

It is a self number, because there is not a number n which added to its sum of digits gives 11121720.

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, 46221 + ... + 46460.

Almost surely, 2^11121720 is an apocalyptic number.

11121720 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

11121720 is an abundant number, since it is smaller than the sum of its proper divisors (22243800).

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

11121720 is a wasteful number, since it uses less digits than its factorization.

11121720 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 92695 (or 92691 counting only the distinct ones).

The product of its (nonzero) digits is 28, while the sum is 15.

The square root of 11121720 is about 3334.9242869966. The cubic root of 11121720 is about 223.2153135008.

Adding to 11121720 its reverse (2712111), we get a palindrome (13833831).

The spelling of 11121720 in words is "eleven million, one hundred twenty-one thousand, seven hundred twenty".