16661954400 has 1152 divisors, whose sum is σ = 72571355136. Its totient is φ = 3223756800.

The previous prime is 16661954389. The next prime is 16661954401. The reversal of 16661954400 is 445916661.

It is a Harshad number since it is a multiple of its sum of digits (42).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (16661954401) by changing a digit.

It is a polite number, since it can be written in 191 ways as a sum of consecutive naturals, for example, 155719147 + ... + 155719253.

It is an arithmetic number, because the mean of its divisors is an integer number (62995968).

Almost surely, 2^16661954400 is an apocalyptic number.

16661954400 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 16661954400, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (36285677568).

16661954400 is an abundant number, since it is smaller than the sum of its proper divisors (55909400736).

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

16661954400 is a wasteful number, since it uses less digits than its factorization.

16661954400 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 204 (or 191 counting only the distinct ones).

The product of its (nonzero) digits is 155520, while the sum is 42.

The spelling of 16661954400 in words is "sixteen billion, six hundred sixty-one million, nine hundred fifty-four thousand, four hundred".