11531611640 has 64 divisors (see below), whose sum is σ = 26291865600. Its totient is φ = 4551322752.

The previous prime is 11531611627. The next prime is 11531611643. The reversal of 11531611640 is 4611613511.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (11531611643) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 3447809 + ... + 3451151.

It is an arithmetic number, because the mean of its divisors is an integer number (410810400).

Almost surely, 2^11531611640 is an apocalyptic number.

11531611640 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 11531611640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (13145932800).

11531611640 is an abundant number, since it is smaller than the sum of its proper divisors (14760253960).

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

11531611640 is a wasteful number, since it uses less digits than its factorization.

11531611640 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4476 (or 4472 counting only the distinct ones).

The product of its (nonzero) digits is 2160, while the sum is 29.

The spelling of 11531611640 in words is "eleven billion, five hundred thirty-one million, six hundred eleven thousand, six hundred forty".