11531817880 has 48 divisors (see below), whose sum is σ = 28519817760. Its totient is φ = 4193386560.

The previous prime is 11531817851. The next prime is 11531817889. The reversal of 11531817880 is 8871813511.

It is a Smith number, since the sum of its digits (43) coincides with the sum of the digits of its prime factors.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (11531817889) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 1186464 + ... + 1196143.

It is an arithmetic number, because the mean of its divisors is an integer number (594162870).

Almost surely, 2^11531817880 is an apocalyptic number.

11531817880 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

11531817880 is an abundant number, since it is smaller than the sum of its proper divisors (16987999880).

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

11531817880 is a wasteful number, since it uses less digits than its factorization.

11531817880 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2382640 (or 2382625 counting only the distinct ones).

The product of its (nonzero) digits is 53760, while the sum is 43.

The spelling of 11531817880 in words is "eleven billion, five hundred thirty-one million, eight hundred seventeen thousand, eight hundred eighty".