11663722640 has 80 divisors (see below), whose sum is σ = 27829687536. Its totient is φ = 4543488000.

The previous prime is 11663722621. The next prime is 11663722649. The reversal of 11663722640 is 4622736611.

It is a happy number.

It can be written as a sum of positive squares in 8 ways, for example, as 1686909184 + 9976813456 = 41072^2 + 99884^2 .

It is a tau number, because it is divible by the number of its divisors (80).

It is a junction number, because it is equal to n+sod(n) for n = 11663722594 and 11663722603.

It is not an unprimeable number, because it can be changed into a prime (11663722649) 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, 2007740 + ... + 2013540.

Almost surely, 2^11663722640 is an apocalyptic number.

11663722640 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 11663722640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (13914843768).

11663722640 is an abundant number, since it is smaller than the sum of its proper divisors (16165964896).

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

11663722640 is a wasteful number, since it uses less digits than its factorization.

11663722640 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6468 (or 6462 counting only the distinct ones).

The product of its (nonzero) digits is 72576, while the sum is 38.

The spelling of 11663722640 in words is "eleven billion, six hundred sixty-three million, seven hundred twenty-two thousand, six hundred forty".