16661309400 has 288 divisors, whose sum is σ = 57563971920. Its totient is φ = 4316160000.

The previous prime is 16661309387. The next prime is 16661309443. The reversal of 16661309400 is 490316661.

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

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 71 ways as a sum of consecutive naturals, for example, 29593519 + ... + 29594081.

Almost surely, 2^16661309400 is an apocalyptic number.

16661309400 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 16661309400, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (28781985960).

16661309400 is an abundant number, since it is smaller than the sum of its proper divisors (40902662520).

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

16661309400 is a wasteful number, since it uses less digits than its factorization.

16661309400 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1027 (or 1015 counting only the distinct ones).

The product of its (nonzero) digits is 23328, while the sum is 36.

The spelling of 16661309400 in words is "sixteen billion, six hundred sixty-one million, three hundred nine thousand, four hundred".