11663721216640 has 64 divisors (see below), whose sum is σ = 27883996638120. Its totient is φ = 4665419366400.

The previous prime is 11663721216611. The next prime is 11663721216661. The reversal of 11663721216640 is 4661212736611.

It is a happy number.

It can be written as a sum of positive squares in 4 ways, for example, as 9827522772544 + 1836198444096 = 3134888^2 + 1355064^2 .

It is a tau number, because it is divible by the number of its divisors (64).

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, 85795120 + ... + 85930960.

Almost surely, 2^{11663721216640} is an apocalyptic number.

11663721216640 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

11663721216640 is an abundant number, since it is smaller than the sum of its proper divisors (16220275421480).

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

11663721216640 is a wasteful number, since it uses less digits than its factorization.

11663721216640 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 270021 (or 270009 counting only the distinct ones).

The product of its (nonzero) digits is 435456, while the sum is 46.

The spelling of 11663721216640 in words is "eleven trillion, six hundred sixty-three billion, seven hundred twenty-one million, two hundred sixteen thousand, six hundred forty".