11661545280 has 672 divisors, whose sum is σ = 48568246272. Its totient is φ = 2341785600.

The previous prime is 11661545243. The next prime is 11661545281. The reversal of 11661545280 is 8254516611.

It is a tau number, because it is divible by the number of its divisors (672).

It is a hoax number, since the sum of its digits (39) coincides with the sum of the digits of its distinct prime factors.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (11661545281) by changing a digit.

It is a polite number, since it can be written in 95 ways as a sum of consecutive naturals, for example, 16040277 + ... + 16041003.

It is an arithmetic number, because the mean of its divisors is an integer number (72274176).

Almost surely, 2^11661545280 is an apocalyptic number.

11661545280 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 11661545280, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (24284123136).

11661545280 is an abundant number, since it is smaller than the sum of its proper divisors (36906700992).

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

11661545280 is a wasteful number, since it uses less digits than its factorization.

11661545280 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 803 (or 786 counting only the distinct ones).

The product of its (nonzero) digits is 57600, while the sum is 39.

The spelling of 11661545280 in words is "eleven billion, six hundred sixty-one million, five hundred forty-five thousand, two hundred eighty".