10661538816 has 220 divisors, whose sum is σ = 32064568272. Its totient is φ = 3528548352.

The previous prime is 10661538791. The next prime is 10661538827. The reversal of 10661538816 is 61883516601.

10661538816 is a `hidden beast` number, since 10 + 6 + 615 + 3 + 8 + 8 + 16 = 666.

It is a super-2 number, since 2×10661538816² (a number of 21 digits) contains 22 as substring.

It is an unprimeable number.

It is a polite number, since it can be written in 19 ways as a sum of consecutive naturals, for example, 14348941 + ... + 14349683.

Almost surely, 2^10661538816 is an apocalyptic number.

10661538816 is a gapful number since it is divisible by the number (16) 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 10661538816, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (16032284136).

10661538816 is an abundant number, since it is smaller than the sum of its proper divisors (21403029456).

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

10661538816 is an equidigital number, since it uses as much as digits as its factorization.

10661538816 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 948 (or 921 counting only the distinct ones).

The product of its (nonzero) digits is 207360, while the sum is 45.

The spelling of 10661538816 in words is "ten billion, six hundred sixty-one million, five hundred thirty-eight thousand, eight hundred sixteen".