16661400 has 96 divisors (see below), whose sum is σ = 59043840. Its totient is φ = 3807360.

The previous prime is 16661369. The next prime is 16661401. The reversal of 16661400 is 416661.

It is a Harshad number since it is a multiple of its sum of digits (24).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (16661401) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 2217 + ... + 6183.

It is an arithmetic number, because the mean of its divisors is an integer number (615040).

Almost surely, 2^16661400 is an apocalyptic number.

16661400 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 16661400, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (29521920).

16661400 is an abundant number, since it is smaller than the sum of its proper divisors (42382440).

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

16661400 is a wasteful number, since it uses less digits than its factorization.

16661400 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3993 (or 3984 counting only the distinct ones).

The product of its (nonzero) digits is 864, while the sum is 24.

The square root of 16661400 is about 4081.8378213741. The cubic root of 16661400 is about 255.4095686543.

The spelling of 16661400 in words is "sixteen million, six hundred sixty-one thousand, four hundred".