16661053440 has 192 divisors, whose sum is σ = 57762549000. Its totient is φ = 4442554368.

The previous prime is 16661053427. The next prime is 16661053459. The reversal of 16661053440 is 4435016661.

It is a happy number.

It is a tau number, because it is divible by the number of its divisors (192).

It is a super-3 number, since 3×16661053440³ (a number of 32 digits) contains 333 as substring.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a junction number, because it is equal to n+sod(n) for n = 16661053395 and 16661053404.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 1468911 + ... + 1480209.

Almost surely, 2^16661053440 is an apocalyptic number.

16661053440 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 16661053440, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (28881274500).

16661053440 is an abundant number, since it is smaller than the sum of its proper divisors (41101495560).

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

16661053440 is an equidigital number, since it uses as much as digits as its factorization.

16661053440 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 11340 (or 11309 counting only the distinct ones).

The product of its (nonzero) digits is 51840, while the sum is 36.

The spelling of 16661053440 in words is "sixteen billion, six hundred sixty-one million, fifty-three thousand, four hundred forty".