11531220 has 24 divisors (see below), whose sum is σ = 32287584. Its totient is φ = 3074976.

The previous prime is 11531207. The next prime is 11531231. The reversal of 11531220 is 2213511.

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 11531220.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 96034 + ... + 96153.

It is an arithmetic number, because the mean of its divisors is an integer number (1345316).

Almost surely, 2^11531220 is an apocalyptic number.

11531220 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

11531220 is an abundant number, since it is smaller than the sum of its proper divisors (20756364).

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

11531220 is a wasteful number, since it uses less digits than its factorization.

11531220 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 192199 (or 192197 counting only the distinct ones).

The product of its (nonzero) digits is 60, while the sum is 15.

The square root of 11531220 is about 3395.7650095376. The cubic root of 11531220 is about 225.9219455306.

Adding to 11531220 its reverse (2213511), we get a palindrome (13744731).

The spelling of 11531220 in words is "eleven million, five hundred thirty-one thousand, two hundred twenty".